The Axis powers (German: Achsenmächte; Italian: Potenze dell'Asse; Japanese: 樞軸國 Sūjikukoku), also known as "Rome–Berlin–Tokyo Axis" (also acronymized as "Roberto"),^[4] were the nations that fought in World War II against the Allies. The Axis powers agreed on their opposition to the Allies, but did not completely coordinate their activity.

The Axis grew out of the diplomatic efforts of Germany, Italy and Japan to secure their own specific expansionist interests in the mid-1930s. The first step was the treaty signed by Germany and Italy in October 1936. Benito Mussolini declared on 1 November that all other European countries would from then on rotate on the Rome–Berlin axis, thus creating the term "Axis".^[5][6] The almost simultaneous second step was the signing in November 1936 of the Anti-Comintern Pact, an anti-communist treaty between Germany and Japan. Italy joined the Pact in 1937. The "Rome–Berlin Axis" became a military alliance in 1939 under the so-called "Pact of Steel", with the Tripartite Pact of 1940 leading to the integration of the military aims of Germany, Italy and Japan.

At its zenith during World War II, the Axis presided over territories that occupied large parts of Europe, North Africa, and East Asia. There were no three-way summit meetings and cooperation and coordination was minimal, with slightly more between Germany and Italy. The war ended in 1945 with the defeat of the Axis powers and the dissolution of their alliance. As in the case of the Allies, membership of the Axis was fluid, with some nations switching sides or changing their degree of military involvement over the course of the war.

The term "axis" was first applied to the Italo-German relationship by the Italian prime minister Benito Mussolini in September 1923, when he wrote in the preface to Roberto Suster's Germania Repubblica that "there is no doubt that in this moment the axis of European history passes through Berlin" (non v'ha dubbio che in questo momento l'asse della storia europea passa per Berlino).^[7] At the time, he was seeking an alliance with the Weimar Republic against Yugoslavia and France in the dispute over the Free State of Fiume.^[8]

The term was used by Hungary's prime minister Gyula Gömbös when advocating an alliance of Hungary with Germany and Italy in the early 1930s.^[9] Gömbös' efforts did affect the Italo-Hungarian Rome Protocols, but his sudden death in 1936 while negotiating with Germany in Munich and the arrival of Kálmán Darányi, his successor, ended Hungary's involvement in pursuing a trilateral axis.^[9] Contentious negotiations between the Italian foreign minister, Galeazzo Ciano, and the German ambassador, Ulrich von Hassell, resulted in a Nineteen-Point Protocol, signed by Ciano and his German counterpart, Konstantin von Neurath, in 1936. When Mussolini publicly announced the signing on 1 November, he proclaimed the creation of a Rome–Berlin axis.^[8]

Italy under Duce Benito Mussolini had pursued a strategic alliance of Italy with Germany against France since the early 1920s.^[10] Prior to becoming head of government in Italy as leader of the Italian Fascist movement, Mussolini had advocated alliance with defeated Germany after the Paris Peace Conference of 1919 settled World War I.^[10] He believed that Italy could expand its influence in Europe by allying with Germany against France.^[10] In early 1923, as a goodwill gesture to Germany, Italy secretly delivered weapons for the German Army, which had faced major disarmament under the provisions of the Treaty of Versailles.^[10]

In September 1923, Mussolini offered German Chancellor Gustav Stresemann a "common policy": he sought German military support against potential French military intervention over Italy's diplomatic dispute with Yugoslavia over Fiume, should an Italian seizure of Fiume result in war between Italy and Yugoslavia. The German ambassador to Italy in 1924 reported that Mussolini saw a nationalist Germany as an essential ally for Italy against France, and hoped to tap into the desire within the German army and the German political right for a war of revenge against France.^[10]

During the Weimar Republic, the German government did not respect the Treaty of Versailles that it had been pressured to sign, and various government figures at the time rejected Germany's post-Versailles borders. General Hans von Seeckt (head of the Reichswehr command from 1920 to 1926) supported an alliance between Germany and the Soviet Union to invade and partition Poland between them and restore the German-Russian border of 1914.^[11] Gustav Streseman as German foreign minister in 1925 declared that the reincorporation of territories lost to Poland and Danzig in the Treaty of Versailles was a major task of German foreign policy.^[11] The Reichswehr Ministry memorandum of 1926 declared its intention to seek the reincorporation of German territory lost to Poland as its first priority, to be followed by the return of the Saar territory, the annexation of Austria, and remilitarization of the Rhineland.^[11]

Since the 1920s Italy had identified the year 1935 as a crucial date for preparing for a war against France, as 1935 was the year when Germany's obligations under the Treaty of Versailles were scheduled to expire.^[12]

Meetings took place in Berlin in 1924 between Italian General Luigi Capello and prominent figures in the German military, such as von Seeckt and Erich Ludendorff, over military collaboration between Germany and Italy. The discussions concluded that Germans still wanted a war of revenge against France but were short on weapons and hoped that Italy could assist Germany.^[13]

However at this time Mussolini stressed one important condition that Italy must pursue in an alliance with Germany: that Italy "must ... tow them, not be towed by them".^[10] Italian foreign minister Dino Grandi in the early 1930s stressed the importance of "decisive weight", involving Italy's relations between France and Germany, in which he recognized that Italy was not yet a major power, but perceived that Italy did have strong enough influence to alter the political situation in Europe by placing the weight of its support onto one side or another.^[14] However Grandi stressed that Italy must seek to avoid becoming a "slave of the rule of three" in order to pursue its interests, arguing that although substantial Italo-French tensions existed, Italy would not unconditionally commit itself to an alliance with Germany, just as it would neither unconditionally commit itself to an alliance with France over conceivable Italo-German tensions.^[15] Grandi's attempts to maintain a diplomatic balance between France and Germany were challenged in 1932 by pressure from the French, who had begun to prepare an alliance with Britain and the United States against the threat of a revanchist Germany.^[16] The French government warned Italy that it had to choose whether to be on the side of the pro-Versailles powers or that of the anti-Versailles revanchists.^[16] Grandi responded that Italy would be willing to offer France support against Germany if France gave Italy its mandate over Cameroon and allowed Italy a free hand in Ethiopia.^[16] France refused Italy's proposed exchange for support, as it believed Italy's demands were unacceptable and the threat from Germany was not yet immediate.^[16]

On 23 October 1932, Mussolini declared support for a Four Power Directorate that included Britain, France, Germany, and Italy, to bring about an orderly treaty revision outside of what he considered the outmoded League of Nations.^[16] The proposed Directorate was pragmatically designed to reduce French hegemony in continental Europe, in order to reduce tensions between the great powers in the short term to buy Italy relief from being pressured into a specific war alliance while at the same time allowing them to benefit from diplomatic deals on treaty revisions.^[16]

In 1932, Gyula Gömbös and the Party of National Unity rose to power in Hungary, and immediately sought an alliance with Italy.^[16] Gömbös sought to alter Hungary's post–Treaty of Trianon borders, but knew that Hungary alone was not capable of challenging the Little Entente powers by forming an alliance with Austria and Italy.^[16] Mussolini was elated by Gömbös' offer of alliance with Italy, and they cooperated in seeking to persuade Austrian Chancellor Engelbert Dollfuss to join a tripartite economic agreement with Italy and Hungary.^[16] At the meeting between Gömbös and Mussolini in Rome on 10 November 1932, the question came up of the sovereignty of Austria in relation to the predicted rise to power in Germany of the Nazi Party.^[16] Mussolini was worried about Nazi ambitions towards Austria, and indicated that at least in the short term he was committed to maintaining Austria as a sovereign state.^[16] Italy had concerns over a Germany which included Austria laying land claims to German-populated territories of the South Tyrol (also known as Alto-Adige) within Italy, which bordered Austria on the Brenner Pass. Gömbös responded to Mussolini that as the Austrians primarily identified as Germans, the Anschluss of Austria to Germany was inevitable, and advised that it would be better for Italy to have a friendly Germany across the Brenner Pass than a hostile Germany bent on entering the Adriatic.^[16] Mussolini said he hoped the Anschluss could be postponed as long as possible until the breakout of a European war that he estimated would begin in 1938.^[16]

In 1933, Adolf Hitler and the Nazi Party came to power in Germany. His first diplomatic visitor was Gömbös. In a letter to Hitler within a day of his being appointed Chancellor, Gömbös told the Hungarian ambassador to Germany to remind Hitler "that ten years ago, on the basis of our common principles and ideology, we were in contact via Dr. Scheubner-Richter".^[17] Gömbös told the Hungarian ambassador to inform Hitler of Hungary's intentions "for the two countries to cooperate in foreign and economic policy".

Hitler had advocated an alliance between Germany and Italy since the 1920s.^[18] Shortly after being appointed Chancellor, Hitler sent a personal message to Mussolini, declaring "admiration and homage" and declaring his anticipation of the prospects of German-Italian friendship and even alliance.^[19] Hitler was aware that Italy held concerns over potential German land claims on South Tyrol, and assured Mussolini that Germany was not interested in South Tyrol. Hitler in Mein Kampf had declared that South Tyrol was a non-issue considering the advantages that would be gained from a German–Italian alliance. After Hitler's rise to power, the Four Power Directorate proposal by Italy had been looked at with interest by Britain, but Hitler was not committed to it, resulting in Mussolini urging Hitler to consider the diplomatic advantages Germany would gain by breaking out of isolation by entering the Directorate and avoiding an immediate armed conflict.^[20] The Four Power Directorate proposal stipulated that Germany would no longer be required to have limited arms and would be granted the right to re-armament under foreign supervision in stages.^[21] Hitler completely rejected the idea of controlled rearmament under foreign supervision.^[21]

Mussolini did not trust Hitler's intentions regarding Anschluss nor Hitler's promise of no territorial claims on South Tyrol.^[22] Mussolini informed Hitler that he was satisfied with the presence of the anti-Marxist government of Dollfuss in Austria, and warned Hitler that he was adamantly opposed to Anschluss.^[22] Hitler responded in contempt to Mussolini that he intended "to throw Dollfuss into the sea".^[22] With this disagreement over Austria, relations between Hitler and Mussolini steadily became more distant.^[22]

Hitler attempted to break the impasse with Italy over Austria by sending Hermann Göring to negotiate with Mussolini in 1933 to convince Mussolini to press the Austrian government to appoint members of Austria's Nazis to the government.^[23] Göring claimed that Nazi domination of Austria was inevitable and that Italy should accept this, as well as repeating to Mussolini of Hitler's promise to "regard the question of the South Tyrol frontier as finally liquidated by the peace treaties".^[23] In response to Göring's visit with Mussolini, Dollfuss immediately went to Italy to counter any German diplomatic headway.^[23] Dollfuss claimed that his government was actively challenging Marxists in Austria and claimed that once the Marxists were defeated in Austria, that support for Austria's Nazis would decline.^[23]

In June 1934, Hitler and Mussolini met for the first time, in Venice. The meeting did not proceed amicably. Hitler demanded that Mussolini compromise on Austria by pressuring Dollfuss to appoint Austrian Nazis to his cabinet, to which Mussolini flatly refused the demand. In response, Hitler promised that he would accept Austria's independence for the time being, saying that due to the internal tensions in Germany (referring to sections of the Nazi SA that Hitler would soon kill in the Night of the Long Knives) that Germany could not afford to provoke Italy.^[24] Galeazzo Ciano told the press that the two leaders had made a "gentleman's agreement" to avoid interfering in Austria.^[25]

Several weeks after the Venice meeting, on 25 July 1934, Austrian Nazis assassinated Dollfuss.^[26] Mussolini was outraged as he held Hitler directly responsible for the assassination that violated Hitler's promise made only weeks ago to respect Austrian independence.^[27][25] Mussolini rapidly deployed several army divisions and air squadrons to the Brenner Pass, and warned that a German move against Austria would result in war between Germany and Italy.^[28] Hitler responded by both denying Nazi responsibility for the assassination and issuing orders to dissolve all ties between the German Nazi Party and its Austrian branch, which Germany claimed was responsible for the political crisis.^[29]

Italy effectively abandoned diplomatic relations with Germany while turning to France in order to challenge Germany's intransigence by signing a Franco-Italian accord to protect Austrian independence.^[30] French and Italian military staff discussed possible military cooperation involving a war with Germany should Hitler dare to attack Austria.

Relations between Germany and Italy recovered due to Hitler's support of Italy's invasion of Ethiopia in 1935, while other countries condemned the invasion and advocated sanctions against Italy.

Interest in Germany and Japan in forming an alliance began when Japanese diplomat Oshima Hiroshi visited Joachim von Ribbentrop in Berlin in 1935.^[31] Oshima informed von Ribbentrop of Japan's interest in forming a German–Japanese alliance against the Soviet Union.^[31] Von Ribbentrop expanded on Oshima's proposal by advocating that the alliance be based in a political context of a pact to oppose the Comintern.^[31] The proposed pact was met with mixed reviews in Japan, with a faction of ultra-nationalists within the government supporting the pact while the Japanese Navy and the Japanese Foreign Ministry were staunchly opposed to the pact.^[32] There was great concern in the Japanese government that such a pact with Germany could disrupt Japan's relations with Britain, endangering years of a beneficial Anglo-Japanese accord, that had allowed Japan to ascend in the international community in the first place.^[33] The response to the pact was met with similar division in Germany; while the proposed pact was popular amongst the upper echelons of the Nazi Party, it was opposed by many in the Foreign Ministry, the Army, and the business community who held financial interests in China to which Japan was hostile.

On learning of German–Japanese negotiations, Italy also began to take an interest in forming an alliance with Japan.^[31] Italy had hoped that due to Japan's long-term close relations with Britain, that an Italo-Japanese alliance could pressure Britain into adopting a more accommodating stance towards Italy in the Mediterranean.^[31] In the summer of 1936, Italian Foreign Minister Ciano informed Japanese Ambassador to Italy, Sugimura Yotaro, "I have heard that a Japanese–German agreement concerning the Soviet Union has been reached, and I think it would be natural for a similar agreement to be made between Italy and Japan".^[31] Initially Japan's attitude towards Italy's proposal was generally dismissive, viewing a German–Japanese alliance against the Soviet Union as imperative while regarding an Italo-Japanese alliance as secondary, as Japan anticipated that an Italo-Japanese alliance would antagonize Britain that had condemned Italy's invasion of Ethiopia.^[31] This attitude by Japan towards Italy altered in 1937 after the League of Nations condemned Japan for aggression in China and faced international isolation, while Italy remained favourable to Japan.^[31] As a result of Italy's support for Japan against international condemnation, Japan took a more positive attitude towards Italy and offered proposals for a non-aggression or neutrality pact with Italy.^[34]

The "Axis powers" formally took the name after the Tripartite Pact was signed by Germany, Italy, and Japan on 27 September 1940, in Berlin. The pact was subsequently joined by Hungary (20 November 1940), Romania (23 November 1940), Slovakia (24 November 1940), and Bulgaria (1 March 1941).^[35]

The Axis powers' primary goal was territorial expansion at the expense of their neighbors.^[36] In ideological terms, the Axis described their goals as breaking the hegemony of the plutocratic Western powers and defending civilization from communism. The Axis championed a number of variants of fascism, militarism, and autarky.^[37]

The Axis population in 1938 was 258.9 million, while the Allied population (excluding the Soviet Union and the United States, which later joined the Allies) was 689.7 million.^[38] Thus the Allied powers outnumbered the Axis powers by 2.7 to 1.^[39] The leading Axis states had the following domestic populations: Germany 75.5 million (including 6.8 million from recently annexed Austria), Japan 71.9 million (excluding its colonies), and Italy 43.4 million (excluding its colonies). The United Kingdom (excluding its colonies) had a population of 47.5 million and France (excluding its colonies) 42 million.^[38]

The wartime gross domestic product (GDP) of the Axis was $911 billion at its highest in 1941 in international dollars by 1990 prices.^[40] The GDP of the Allied powers was $1,798 billion. The United States stood at $1,094 billion, more than the Axis combined.^[41]

The burden of the war upon participating countries has been measured through the percentage of gross national product (GNP) devoted to military expenditures.^[42] Nearly one-quarter of Germany's GNP was committed to the war effort in 1939, and this rose to three-quarters of GNP in 1944, prior to the collapse of the economy.^[42] In 1939, Japan committed 22 percent of its GNP to its war effort in China; this rose to three-quarters of GNP in 1944.^[42] Italy did not mobilize its economy; its GNP committed to the war effort remained at prewar levels.^[42]

Italy and Japan lacked industrial capacity; their economies were small, dependent on international trade, external sources of fuel and other industrial resources.^[42] As a result, Italian and Japanese mobilization remained low, even by 1943.^[42]

Among the three major Axis powers, Japan had the lowest per capita income, while Germany and Italy had an income level comparable to the United Kingdom.^[43]

Hitler in 1941 described the outbreak of World War II as the fault of the intervention of Western powers against Germany during its war with Poland, describing it as the result of "the European and American warmongers".^[44] Hitler denied accusations by the Allies that he wanted a World War, and invoked anti-Semitic claims that the war was wanted and provoked by politicians of Jewish origin or associated with Jewish interests.^[45] However Hitler clearly had designs for Germany to become the dominant and leading state in the world, such as his intention for Germany's capital of Berlin to become the Welthauptstadt ("World Capital"), renamed Germania.^[46] The German government also justified its actions by claiming that Germany inevitably needed to territorially expand because it was facing an overpopulation crisis that Hitler described: "We are overpopulated and cannot feed ourselves from our own resources".^[47] Thus expansion was justified as an inevitable necessity to provide lebensraum ("living space") for the German nation and end the country's overpopulation within existing confined territory, and provide resources necessary to its people's well-being.^[47] Since the 1920s, the Nazi Party publicly promoted the expansion of Germany into territories held by the Soviet Union.^[48] However, from 1939 to 1941, the Nazi regime claimed to have discarded those plans in light of improved relations with the Soviet Union via the Molotov–Ribbentrop Pact, and claimed that central Africa was where Germany sought to achieve lebensraum.^[49] Hitler publicly claimed that Germany wanted to settle the lebensraum issue peacefully through diplomatic negotiations that would require other powers to make concessions to Germany.^[50] At the same time however Germany did prepare for war in the cause of lebensraum, and in the late 1930s Hitler emphasized the need for a military build-up to prepare for a potential clash between the peoples of Germany and the Soviet Union.^[51]

Germany justified its war against Poland on the issues of German minority within Poland and Polish opposition to the incorporation of the ethnically German-majority Free City of Danzig into Germany. While Hitler and the Nazi party before taking power openly talked about destroying Poland and were hostile to Poles, after gaining power until February 1939 Hitler tried to conceal his true intentions towards Poland, and signed a 10-year Non-Aggression Pact in 1934, revealing his plans to only to his closest associates.^[52] Relations between Germany and Poland altered from the early to the late 1930s, as Germany sought rapprochement with Poland to avoid the risk of Poland entering the Soviet sphere of influence, and appealed to anti-Soviet sentiment in Poland.^[53] The Soviet Union in turn at this time competed with Germany for influence in Poland.^[53] At the same time Germany was preparing for a war with Poland and was secretly preparing the German minority in Poland for a war.^[54] And since 1935 weapons were being smuggled and gathered in frontier Polish regions by German intelligence.^[55] In November 1938, Germany organized German paramilitary units in the Polish region of Pomerania that were trained to engage in diversion, sabotage as well as murder and ethnic cleansing upon a German invasion of Poland.^[55] At the end of 1938 one of the first editions of Sonderfahndungsbuch Polen was printed by the Nazis, containing several thousand names of Poles targeted for execution and imprisonment after an invasion of Poland^[56] From late 1938 to early 1939, Germany in talks with Poland suggested that as reward for Poland transferring territories in Pomerania to Germany that Poland could annex Ukrainian territories from the Soviet Union after a war with Soviet Union.^[57] In January 1939, Ribbentrop held negotiations with Józef Beck, the Polish minister of foreign affairs; and Edward Rydz-Śmigły, the commander-in-chief of the Polish Army; in which Ribbentrop urged them to have Poland enter the Anti-Comintern Pact and work together with Germany for a mutual war in the East, whereby Poland would take Slovakia and Ukraine.^[57] Ribbentrop in private discussion with German officials stated that he hoped that by offering Poland large new territories in the Soviet Union, that Germany would gain not only from Polish cooperation in a war with the Soviet Union, but also that Poland would cooperate by transferring the Polish Corridor to Germany in exchange for these gains, because though it would lose access to the Baltic Sea, it would gain access to the Black Sea via Ukraine.^[57] However Beck refused to discuss German demands for the Corridor and was recalcitrant to the idea of a war with the Soviet Union.^[57] The Polish government distrusted Hitler and saw the plan as a threat to Polish sovereignty, practically subordinating Poland to the Axis and the Anti-Comintern Bloc while reducing the country to a state of near-servitude as its entire trade with Western Europe through the Baltic Sea would become dependent on Germany.^[58]

A diplomatic crisis erupted following Hitler demanding that the Free City of Danzig be annexed to Germany, as it was led by a Nazi government seeking annexation to Germany. Germany used legal precedents to justify its intervention against Poland and annexation of the Free City of Danzig (led by a local Nazi government that sought incorporation into Germany) in 1939.^[59] Germany noted one such violation as being in 1933 when Poland sent additional troops into the city in violation of the limit of Polish troops admissible to Danzig as agreed to by treaty.^[59] Hitler believed that Poland could be pressured to cede claimed territory through diplomatic means combined with the threat of military force, and believed that Germany could gain such concessions from Poland without provoking a war with Britain or France.^[60] Hitler believed that Britain's guarantee of military support to Poland was a bluff, and with a German-Soviet agreement on both countries recognizing their mutual interests involving Poland.^[60] The Soviet Union had diplomatic grievances with Poland since the Soviet-Polish War of 1919–1921 in which the Soviets agreed that North-eastern Poland, Western Belarus and Western Ukraine will become part of restored Polish state after intense fighting in those years over the territories, and the Soviet Union sought to regain those territories.^[61]

Poland rejected Germany's demands and Germany in response prepared a general mobilization on the morning of 30 August 1939.^[62] Hitler believed that one of two outcomes would occur. The first was that the British would accept Germany's demands and pressure Poland to agree to them.^[62] The second was that a conflict with Poland would be an isolated conflict, as Britain would not engage in a war with both Germany and the Soviet Union.^[60] At midnight 30 August 1939, German foreign minister Joachim Ribbentrop was expecting the arrival of the British ambassador Nevile Henderson as well as a Polish plenipotentiary to negotiate terms with Germany.^[62] Only Henderson arrived, and Henderson informed Ribbentrop that no Polish plenipotentiary was arriving.^[62] Ribbentrop became extremely upset and demanded the immediate arrival of a Polish diplomat, informing Henderson that the situation was "damned serious!", and read out to Henderson Germany's demands that Poland accept Germany annexing Danzig as well as Poland granting Germany the right to increase the connection of the infrastructure of East Prussia to mainland Germany by building an extraterritorial highway and railway that passed through the Polish Gdansk Pomerania, and a plebiscite to determine whether the Polish Corridor, that had a mixed composition of ethnic Poles and ethnic Germans, should remain within Poland or be transferred to Germany.^[62]

Germany justified its invasion of the Low Countries of Belgium, Luxembourg, and the Netherlands in May 1940 by claiming that it suspected that Britain and France were preparing to use the Low Countries to launch an invasion of the industrial Ruhr region of Germany.^[63] When war between Germany versus Britain and France appeared likely in May 1939, Hitler declared that the Netherlands and Belgium would need to be occupied, saying: "Dutch and Belgian air bases must be occupied ... Declarations of neutrality must be ignored".^[63] In a conference with Germany's military leaders on 23 November 1939, Hitler declared to the military leaders that "We have an Achilles heel, the Ruhr", and said that "If England and France push through Belgium and Holland into the Ruhr, we shall be in the greatest danger", and thus claimed that Belgium and the Netherlands had to be occupied by Germany to protect Germany from a British-French offensive against the Ruhr, irrespective of their claims to neutrality.^[63]

In April 1941, shortly after Germany and Yugoslavia completed negotiations for Yugoslavia to join the Axis, a coup d'état occurred in Yugoslavia that led to the Axis invasion of Yugoslavia. Germany needed access to the territory held by Yugoslavia to allow German forces to have a direct route to travel through, to reach and rescue Italian military forces that were faltering in their campaign in Greece. There was substantial animosity towards the alliance amongst Serbs, Yugoslavia's largest ethnic group, who had fought German Austrians and Germany on the side of the Allies in World War I, and three Serb cabinet ministers resigned their positions in protest after the alliance was signed. Hitler initially attempted to be conciliatory to the Serbs who held animosity to the agreement, saying that he "understood the feelings" of those Serbs who opposed the alliance. Amidst the negotiations, Hitler expressed concern to Italian foreign minister Ciano that he sensed trouble coming in Belgrade. A coup d'état occurred in Yugoslavia in which a government rose to power and abandoned its association with the Axis. Hitler accused the coup of being engineered by the British. The coup was at least partly supported by the British though there was substantial patriotic enthusiasm against the Pact with rallies in Belgrade. At the rallies in Belgrade immediately after the coup, people were heard to be shouting "Better war than pact!" and waving British, American, and French flags. Days after the coup d'état, Hitler ordered the German General Staff to plan for an invasion of Yugoslavia.^[64]

Germany's invasion of the Soviet Union in 1941 involved issues of lebensraum, anti-communism, and Soviet foreign policy. Hitler in his early years as Nazi leader had claimed that he would be willing to accept friendly relations with Russia on the tactical condition that Russia agree to return to the borders established by the German–Russian peace agreement of the Treaty of Brest-Litovsk signed by Vladimir Lenin of the Russian Soviet Federated Socialist Republic in 1918 which gave large territories held by Russia to German control in exchange for peace.^[48] Hitler in 1921 had commended the Treaty of Brest Litovsk as opening the possibility for restoration of relations between Germany and Russia, saying:

From 1921 to 1922 Hitler evoked rhetoric of both the achievement of lebensraum involving the acceptance of a territorially reduced Russia as well as supporting Russian nationals in overthrowing the Bolshevik government and establishing a new Russian government.^[48] However Hitler's attitudes changed by the end of 1922, in which he then supported an alliance of Germany with Britain to destroy Russia.^[48] Later Hitler declared how far into Russia he intended to expand Germany to:

Policy for lebensraum planned mass expansion of Germany's borders as far eastwards as the Ural Mountains.^[65][66] Hitler planned for the "surplus" Russian population living west of the Urals to be deported to the east of the Urals.^[67] After Germany invaded the Soviet Union in 1941, the Nazi regime's stance towards an independent, territorially-reduced Russia was affected by pressure beginning in 1942 from the German Army on Hitler to endorse a Russian national liberation army led by Andrey Vlasov that officially sought to overthrow Joseph Stalin and the communist regime and establish a new Russian state.^[68] Initially the proposal to support an anti-communist Russian army was met with outright rejection by Hitler, however by 1944 as Germany faced mounting losses on the Eastern Front, Vlasov's forces were recognized by Germany as an ally, particularly by Reichsführer-SS Heinrich Himmler.^[69]

After the Molotov–Ribbentrop Pact was signed, in 1940 when Molotov arrived in Berlin on a diplomatic visit during which Ribbentrop stated that Germany was directing its lebensraum southward.^[70] Ribbentrop described to Molotov that further extension of Germany's lebensraum was now going to be founded in Central Africa, and suggested that Germany would accept the Soviet Union taking part in the partitioning of the British Empire upon a British defeat in the war.^[49]

Germany and the Soviet Union in 1940 were in dispute over their respective influences in the Balkans, Bulgaria, the Danube and the Turkish Straits. The Soviet seizure of Bessarabia from Romania in June 1940 placed the Soviet–Romanian frontier dangerously close to Romania's oil fields in Ploiești that Germany needed oil trade from to support its war effort.^[71] When negotiations with Molotov led to no resolution, Hitler determined that Britain was only continuing to fight in hope of Soviet intervention and therefore the defeat of the Soviet Union would result in the defeat of Britain and in July 1940 began planning for a possible invasion of the Soviet Union.^[71]

After the Japanese attack on Pearl Harbor and the outbreak of war between Japan and the United States, Germany supported Japan by declaring war on the US. During the war Germany denounced the Atlantic Charter and the Lend-Lease Act that the US adopted to support the Allied powers prior to entry into the alliance, as imperialism directed at dominating and exploit countries outside of the continental Americas.^[72] Hitler denounced American President Roosevelt's invoking of the term "freedom" to describe US actions in the war, and accused the American meaning of "freedom" to be the freedom for democracy to exploit the world and the freedom for plutocrats within such democracy to exploit the masses.^[72]

At the end of World War I, German citizens felt that their country had been humiliated as a result of the Treaty of Versailles, which included a war guilt clause and forced Germany to pay enormous reparations payments and forfeit territories formerly controlled by German Empire and all its colonies. The pressure of the reparations on the German economy led to hyperinflation during the early 1920s. In 1923 the French occupied the Ruhr region when Germany defaulted on its reparations payments. Although Germany began to improve economically in the mid-1920s, the Great Depression created more economic hardship and a rise in political forces that advocated radical solutions to Germany's woes. The Nazis, under Hitler, promoted the nationalist stab-in-the-back legend stating that Germany had been betrayed by Jews and Communists. The party promised to rebuild Germany as a major power and create a Greater Germany that would include Alsace-Lorraine, Austria, Sudetenland, and other German-populated territories in Europe. The Nazis also aimed to occupy and colonize non-German territories in Poland, the Baltic states, and the Soviet Union, as part of the Nazi policy of seeking Lebensraum ("living space") in eastern Europe.

Germany renounced the Versailles treaty and remilitarized the Rhineland in March 1936. Germany had already resumed conscription and announced the existence of a German air force, the Luftwaffe, and naval force, the Kriegsmarine in 1935. Germany annexed Austria in 1938, the Sudetenland from Czechoslovakia, and the Memel territory from Lithuania in 1939. Germany then invaded the rest of Czechoslovakia in 1939, creating the Protectorate of Bohemia and Moravia and the country of Slovakia.

On 23 August 1939, Germany and the Soviet Union signed the Molotov–Ribbentrop Pact, which contained a secret protocol dividing eastern Europe into spheres of influence.^[73] Germany's invasion of its part of Poland under the Pact eight days later^[74] triggered the beginning of World War II. By the end of 1941, Germany occupied a large part of Europe and its military forces were fighting the Soviet Union, nearly capturing Moscow. However, crushing defeats at the Battle of Stalingrad and the Battle of Kursk devastated the German armed forces. This, combined with Western Allied landings in France and Italy, led to a three-front war that depleted Germany's armed forces and resulted in Germany's defeat in 1945.

There was substantial internal opposition within the German military to the Nazi regime's aggressive strategy of rearmament and foreign policy in the 1930s.^[75] From 1936 to 1938, Germany's top four military leaders, Ludwig Beck, Werner von Blomberg, Werner von Fritsch, Walther von Reichenau, were all in opposition to the rearmament strategy and foreign policy.^[76] They criticized the hurried nature of rearmament, the lack of planning, Germany's insufficient resources to carry out a war, the dangerous implications of Hitler's foreign policy, and the increasing subordination of the army to the Nazi Party's rules.^[76] These four military leaders were outspoken and public in their opposition to these tendencies.^[76] The Nazi regime responded with contempt to the four military leaders' opposition, and Nazi members brewed a false crass scandal that alleged that the two top army leaders von Blomberg and von Fritsch were homosexual lovers, in order to pressure them to resign.^[76] Though started by lower-ranking Nazi members, Hitler took advantage of the scandal by forcing von Blomberg and von Fritsch to resign and replaced them with opportunists who were subservient to him.^[76] Shortly afterwards Hitler announced on 4 February 1938 that he was taking personal command over Germany's military with the new High Command of the Armed Forces with the Führer as its head.^[76]

The opposition to the Nazi regime's aggressive foreign policy in the military became so strong from 1936 to 1938, that considerations of overthrowing the Nazi regime were discussed within the upper echelons of the military and remaining non-Nazi members of the German government.^[77] Minister of Economics, Hjalmar Schacht met with Beck in 1936 in which Schacht declared to Beck that he was considering an overthrow of the Nazi regime and was inquiring what the stance was by the German military on support of an overthrow of the Nazi regime.^[77] Beck was lukewarm to the idea, and responded that if a coup against the Nazi regime began with support at the civilian level, the military would not oppose it.^[77] Schacht considered this promise by Beck to be inadequate because he knew that without the support of the army, any coup attempt would be crushed by the Gestapo and the SS.^[78] However, by 1938, Beck became a firm opponent of the Nazi regime out of his opposition to Hitler's military plans of 1937–38 that told the military to prepare for the possibility of a world war as a result of German annexation plans for Austria and Czechoslovakia.^[78]

The Protectorate of Bohemia and Moravia was created from the dismemberment of Czechoslovakia. Shortly after Germany annexed the Sudetenland region of Czechoslovakia, Slovakia declared its independence. The new Slovak State allied itself with Germany. The remainder of the country was occupied by German military forces and organized into the Protectorate. Czech civil institutions were preserved but the Protectorate was considered within the sovereign territory of Germany.

The General Government was the name given to the territories of occupied Poland that were not directly annexed into German provinces, but like Bohemia and Moravia was considered within the sovereign territory of Germany.

Belgium quickly surrendered to Germany, and the Belgian King remained in the country during the German military occupation from 1940 to 1944. The Belgian King cooperated closely with Germany and repeatedly sought assurances that Belgian rights would be retained once Germany achieved total victory. However, Hitler intended to annex Belgium and its Germanic population into the Greater Germanic Reich, initiated by the creation of Reichskommissariat Belgien, an authority run directly by the German government that sought the incorporation of the territory into the planned Germanic Reich. However Belgium was soon occupied by Allied forces in 1944.

Reichskommissariat Niederlande was an occupation authority and territory established in the Netherlands in 1940 designated as a colony to be incorporated into the planned Greater Germanic Reich.

Reichskommissariat Norwegen was established in Norway in 1940. Like the Reichskommissariats in Belgium and the Netherlands, its Germanic peoples were to be incorporated into the Greater Germanic Reich. In Norway, the Quisling regime, headed by Vidkun Quisling, was installed by the Germans as a client regime during the occupation, while king Haakon VII and the legal government were in exile. Quisling encouraged Norwegians to serve as volunteers in the Waffen-SS, collaborated in the deportation of Jews, and was responsible for the executions of members of the Norwegian resistance movement.

About 45,000 Norwegian collaborators joined the pro-Nazi party Nasjonal Samling (National Union), and some police units helped arrest many Jews. However, Norway was one of the first countries where resistance during World War II was widespread before the turning point of the war in 1943. After the war, Quisling and other collaborators were executed. Quisling's name has become an international eponym for traitor.

Reichskommissariat Ostland was established in the Baltic region in 1941. Unlike the western Reichskommissariats that sought the incorporation of their majority Germanic peoples, Ostland were designed for settlement by Germans who would displace the non-Germanic majority living there, as part of lebensraum.

Reichskommissariat Ukraine was established in Ukraine in 1941. Like Ostland it was slated for settlement by Germans.

The Military Administration in Serbia was established on occupied Yugoslav territory in April 1941, following the invasion of the country. On 30 April a pro-German Serbian administration was formed under Milan Aćimović to serve as a civil administration in the military occupation zone. A joint Partisan and Chetnik uprising in late 1941 became a serious concern for the Germans, as most of their forces were deployed to Russia; only three divisions were in the country. On 13 August 546 Serbs, including some of the country's prominent and influential leaders, issued an appeal to the Serbian nation that condemned the Partisan and royalist resistance as unpatriotic. Two weeks after the appeal, with the Partisan and royalist insurgency beginning to gain momentum, 75 prominent Serbs convened a meeting in Belgrade and formed a Government of National Salvation under Serbian General Milan Nedić to replace the existing Serbian administration. The Germans were short of police and military forces in Serbia, and came to rely on poorly armed Serbian formations, the Serbian State Guard and Serbian Volunteer Corps, to maintain order. These forces, however, were not able to contain the resistance, and for the most of the war large parts of Serbia were under control of the Partisans or Chetniks (the two resistance movements soon became mutually-hostile). The Government of National Salvation, imbued with few powers upon formation, saw its functions further decreased and taken over by the Wehrmacht occupation authorities as the war progressed. After the initial mass revolts, the German authorities instituted an extreme regime of reprisals, proclaiming that 100 civilians would be executed for every German soldier killed, and 50 for each one wounded. These measures were actually implemented on more than one occasion: large-scale shootings took place in the Serbian towns of Kraljevo and Kragujevac during October 1941.

Duce Benito Mussolini described Italy's declaration of war against the Western Allies of Britain and France in June 1940 as the following: "We are going to war against the plutocratic and reactionary democracies of the West who have invariably hindered the progress and often threatened the very existence of the Italian people".^[79] Italy condemned the Western powers for enacting sanctions on Italy in 1935 for its actions in the Second Italo-Ethiopian War that Italy claimed was a response to an act of Ethiopian aggression against tribesmen in Italian Eritrea in the Walwal incident of 1934.^[80] Italy, like Germany, also justified its actions by claiming that Italy needed to territorially expand to provide spazio vitale ("vital space") for the Italian nation.^[81]

In October 1938 in the aftermath of the Munich Agreement, Italy demanded concessions from France to yield to Italy: a free port at Djibouti, control of the Addis Ababa-Djibouti railroad, Italian participation in the management of Suez Canal Company, some form of French-Italian condominium over Tunisia, and the preservation of Italian culture in French-held Corsica with no French assimilation of the people.^[82] Italy opposed the French monopoly over the Suez Canal because under the French-dominated Suez Canal Company all Italian merchant traffic to its colony of Italian East Africa was forced to pay tolls upon entering the canal.^[82][83] Mussolini hoped that in light of Italy's role in settling the Munich Agreement that prevented the outbreak of war, that Britain would react by putting pressure on France to yield to Italy's demands to preserve the peace.^[82] France refused to accept Italy's demands as it was widely suspected that Italy's true intentions were territorial acquisition of Nice, Corsica, Tunisia, and Djibouti and not the milder official demands put forth.^[82] Relations between Italy and France deteriorated with France's refusal to accept Italy's demands.^[82] France responded to Italy's demands with threatening naval maneuvers as a warning to Italy.^[82] As tensions between Italy and France grew, Hitler made a major speech on 30 January 1939 in which he promised German military support in the case of an unprovoked war against Italy.^[84]

Italy justified its intervention against Greece in October 1940 on the allegation that Greece was being used by Britain against Italy, Mussolini informed this to Hitler, saying: "Greece is one of the main points of English maritime strategy in the Mediterranean".^[85]

Italy justified its intervention against Yugoslavia in April 1941 by appealing to both Italian irredentist claims and the fact of Albanian, Croatian, and Macedonian separatists not wishing to be part of Yugoslavia.^[86] Croatian separatism soared after the assassination of Croatian political leaders in the Yugoslav parliament in 1928 including the death of Stjepan Radić, and Italy endorsed Croatian separatist Ante Pavelić and his fascist Ustaše movement that was based and trained in Italy with the Fascist regime's support prior to intervention against Yugoslavia.^[86]

In the late 19th century, after Italian unification, a nationalist movement had grown around the concept of Italia irredenta, which advocated the incorporation into Italy of Italian-populated areas still under foreign rule. There was a desire to annex Dalmatian territories, which had formerly been ruled by the Venetians, and which consequently had Italian-speaking elites. The intention of the Fascist regime was to create a "New Roman Empire" in which Italy would dominate the Mediterranean. In 1935–1936 Italy invaded and annexed Ethiopia and the Fascist government proclaimed the creation of the "Italian Empire".^[87] Protests by the League of Nations, especially the British, who had interests in that area, led to no serious action, although The League did try to enforce economic sanctions upon Italy, but to no avail. The incident highlighted French and British weakness, exemplified by their reluctance to alienate Italy and lose her as their ally. The limited actions taken by the Western powers pushed Mussolini's Italy towards alliance with Hitler's Germany anyway. In 1937 Italy left the League of Nations and joined the Anti-Comintern Pact, which had been signed by Germany and Japan the preceding year. In March/April 1939 Italian troops invaded and annexed Albania. Germany and Italy signed the Pact of Steel on May 22.

Italy entered World War II on 10 June 1940. In September 1940 Germany, Italy, and Japan signed the Tripartite Pact.

Italy was ill-prepared for war, in spite of the fact that it had continuously been involved in conflict since 1935, first with Ethiopia in 1935–1936 and then in the Spanish Civil War on the side of Francisco Franco's Nationalists.^[88] Mussolini refused to heed warnings from his minister of exchange and currency, Felice Guarneri, who said that Italy's actions in Ethiopia and Spain meant that Italy was on the verge of bankruptcy.^[89] By 1939 military expenditures by Britain and France far exceeded what Italy could afford.^[89] As a result of Italy's economic difficulties its soldiers were poorly paid, often being poorly equipped and poorly supplied, and animosity arose between soldiers and class-conscious officers; these contributed to low morale amongst Italian soldiers.^[90] Military planning was deficient, as the Italian government had not decided on which theatre would be the most important. Power over the military was overcentralized to Mussolini's direct control; he personally undertook to direct the ministry of war, the navy, and the air force. The navy did not have any aircraft carriers to provide air cover for amphibious assaults in the Mediterranean, as the Fascist regime believed that the air bases on the Italian Peninsula would be able to do this task.^[91] Italy's army had outmoded artillery and the armoured units used outdated formations not suited to modern warfare.^[92] Diversion of funds to the air force and navy to prepare for overseas operations meant less money was available for the army; the standard rifle was a design that dated back to 1891.^[89] The Fascist government failed to learn from mistakes made in Ethiopia and Spain; it ignored the implications of the Italian Fascist volunteer soldiers being routed at the Battle of Guadalajara in the Spanish Civil War.^[89] Military exercises by the army in the Po Valley in August 1939 disappointed onlookers, including King Victor Emmanuel III.^[92] Mussolini who was angered by Italy's military unpreparedness, dismissed Alberto Pariani as Chief of Staff of the Italian military in 1939.^[93]

Italy's only strategic natural resource was an abundance of aluminum. Petroleum, iron, copper, nickel, chrome, and rubber all had to be imported.^[92] The Fascist government's economic policy of autarky and a recourse to synthetic materials was not able to meet the demand.^[88] Prior to entering the war, the Fascist government sought to gain control over resources in the Balkans, particularly oil from Romania.^[94] The agreement between Germany and the Soviet Union to invade and partition Poland between them resulted in Hungary that bordered the Soviet Union after Poland's partition, and Romania viewing Soviet invasion as an immediate threat, resulting in both countries appealing to Italy for support, beginning in September 1939.^[93] Italy – then still officially neutral – responded to appeals by the Hungarian and Romanian governments for protection from the Soviet Union, by proposing a Danube-Balkan neutrals bloc.^[93] The proposed bloc was designed to increase Italian influence in the Balkans: it met resistance from France, Germany, and the Soviet Union that did not want to lose their influence in the Balkans; however Britain, who believed that Italy would not enter the war on Germany's side, supported the neutral bloc.^[93] The efforts to form the bloc failed by November 1939 after Turkey made an agreement that it would protect Allied Mediterranean territory, along with Greece and Romania.^[93]

Initially upon the outbreak of war between Germany and the Allies, Mussolini pursued a non-belligerent role for Italy out of concerns that Germany may not win its war with the Allies. However Mussolini in private grew anxious that Italy not intervening in support of Germany in September 1939 upon Britain and France waging war on Germany, would eventually result in retribution by Germany if Italy did not get involved in the war on Germany's side.^[95]

By early 1940, Italy was still a non-belligerent, and Mussolini communicated to Hitler that Italy was not prepared to intervene soon. By March 1940, Mussolini decided that Italy would intervene, but the date was not yet chosen. His senior military leadership unanimously opposed the action because Italy was unprepared. No raw materials had been stockpiled and the reserves it did have would soon be exhausted, Italy's industrial base was only one-tenth of Germany's, and even with supplies the Italian military was not organized to provide the equipment needed to fight a modern war of a long duration. An ambitious rearmament program was impossible because of Italy's limited reserves in gold and foreign currencies and lack of raw materials. Mussolini ignored the negative advice.^[96]

An April 1938 report by German Naval High Command (OKM) warned that Italy as a combatant ally would be a serious "burden" to Germany if a war between Germany and Britain occurred, and recommended that it would be preferable for Germany to seek for Italy to be a "benevolent neutral" during the war. On 18 March 1940, Hitler told Mussolini in person that the war would be over by the summer and that Italy's military involvement was not required.^[97]

Mussolini on 29 May 1940 discussed the situation of the Italian Army in which he acknowledged that it was not ideal but believed that it was satisfactory, and discussed the timeline for a declaration of war on Britain and France. He said: "a delay of two weeks or a month would not be an improvement, and Germany could think we entered the war when the risk was very small ... And this could be a burden on us when peace comes."^[98]

After entering the war in 1940, Italy had been slated to be granted a series of territorial concessions from France that Hitler had agreed to with Italian foreign minister Ciano, that included Italian annexation of claimed territories in southeastern France, a military occupation of southeastern France up to the river Rhone, and receiving the French colonies of Tunisia and Djibouti.^[99] However, on 22 June 1940, Mussolini suddenly informed Hitler that Italy was abandoning its claims "in the Rhone, Corsica, Tunisia, and Djibouti", instead requesting a demilitarized zone along the French border, and on 24 June Italy agreed to an armistice with the Vichy regime to that effect.^[99] Later on 7 July 1940, the Italian government changed its decision, and Ciano attempted to make an agreement with Hitler to have Nice, Corsica, Tunisia, and Djibouti be transferred to Italy; Hitler adamantly rejected any new settlement or separate French-Italian peace agreement for the time being prior to the defeat of Britain in the war.^[99] However Italy continued to press Germany for the incorporation of Nice, Corsica, and Tunisia into Italy, with Mussolini sending a letter to Hitler in October 1940, informing him that as the 850,000 Italians living under France's current borders formed the largest minority community, that ceding these territories to Italy would be beneficial to both Germany and Italy as it would reduce France's population from 35 million to 34 and forestall any possibility of resumed French ambitions for expansion or hegemony in Europe.^[99] Germany had considered the possibility of invading and occupying the non-occupied territories of Vichy France including occupying Corsica; Germany capturing the Vichy French fleet for use by Germany, in December 1940 with the proposed Operation Attila.^[100] An invasion of Vichy France by Germany and Italy took place with Case Anton in November 1942.

In mid-1940, in response to an agreement by Romanian Conducător Ion Antonescu to accept German "training troops" to be sent to Romania, both Mussolini and Stalin in the Soviet Union were angered by Germany's expanding sphere of influence into Romania, and especially because neither was informed in advance of the action in spite of German agreements with Italy and the Soviet Union at that time.^[85] Mussolini in a conversation with Ciano responded to Hitler's deployment of troops into Romania, saying: "Hitler always faces me with accomplished facts. Now I'll pay him back by his same currency. He'll learn from the papers that I have occupied Greece. So the balance will be re-established."^[85] However Mussolini later decided to inform Hitler in advance of Italy's designs on Greece.^[85] Upon hearing of Italy's intervention against Greece, Hitler was deeply concerned as he said that the Greeks were not bad soldiers that Italy might not win in its war with Greece, as he did not want Germany to become embroiled in a Balkan conflict.^[85]

By 1941, Italy's attempts to run an autonomous campaign from Germany's, collapsed as a result of military setbacks in Greece, North Africa, and Eastern Africa; and the country became dependent and effectively subordinate to Germany. After the German-led invasion and occupation of Yugoslavia and Greece, that had both been targets of Italy's war aims, Italy was forced to accept German dominance in the two occupied countries.^[101] Furthermore, by 1941, German forces in North Africa under Erwin Rommel effectively took charge of the military effort ousting Allied forces from the Italian colony of Libya, and German forces were stationed in Sicily in that year.^[102] Germany's insolence towards Italy as an ally was demonstrated that year when Italy was pressured to send 350,000 "guest workers" to Germany who were used as forced labour.^[103] While Hitler was disappointed with the Italian military's performance, he maintained overall favorable relations with Italy because of his personal friendship with Mussolini.^[104]

Mussolini by mid-1941 recognized that Italy's war objectives had failed.^[101] Mussolini henceforth believed that Italy was left with no choice in such a subordinate status other than to follow Germany in its war and hope for a German victory.^[101] However Germany supported Italian propaganda of the creation of a "Latin Bloc" of Italy, Vichy France, Spain, and Portugal to ally with Germany against the threat of communism, and after the German invasion of the Soviet Union, the prospect of a Latin Bloc seemed plausible.^[105] From 1940 to 1941, Francisco Franco of Spain had endorsed a Latin Bloc of Italy, Vichy France, Spain and Portugal, in order to balance the countries' powers to that of Germany; however, the discussions failed to yield an agreement.^[106]

After the invasion and occupation of Yugoslavia, Italy annexed numerous Adriatic islands and a portion of Dalmatia that was formed into the Italian Governorship of Dalmatia including territory from the provinces of Spalato, Zara, and Cattaro.^[107] Though Italy had initially larger territorial aims that extended from the Velebit mountains to the Albanian Alps, Mussolini decided against annexing further territories due to a number of factors, including that Italy held the economically valuable portion of that territory within its possession while the northern Adriatic coast had no important railways or roads and because a larger annexation would have included hundreds of thousands of Slavs who were hostile to Italy, within its national borders.^[107] Mussolini and foreign minister Ciano demanded that the Yugoslav region of Slovenia to be directly annexed into Italy, however in negotiations with German foreign minister Ribbentrop in April 1941, Ribbentrop insisted on Hitler's demands that Germany be allocated the eastern Slovenia while Italy would be allocated western Slovenia, Italy conceded to this German demand and Slovenia was partitioned between Germany and Italy.^[108]

With the commencing of the Allies' Operation Torch against Vichy French-held Morocco and Algeria, Germany and Italy intervened in Vichy France and in Vichy French-held Tunisia. Italy seized military control over a significant portion of southern France and Corsica, while a joint German-Italian force seized control over most of Tunisia.^[109] When the issue of sovereign control over Tunisia arose from seizure of control by the German-Italian force from Vichy French control, Ribbentrop proclaimed Italian predominance in Tunisia.^[109] However, in spite of Germany's claim to respect Italian predominance, Germans supervised public services and local government in Tunisia, and the German presence was more popular in Tunisia with both the local Arab population and Vichy French collaborators since Germany had no imperial aspirations in Tunisia while Italy did.^[109]

Internal opposition by Italians to the war and the Fascist regime accelerated by 1942, though significant opposition to the war had existed at the outset in 1940, as police reports indicated that many Italians were secretly listening to the BBC rather than Italian media in 1940.^[110] Underground Catholic, Communist, and socialist newspapers began to become prominent by 1942.^[111]

In spring 1941, Victor Emmanuel III visited Italian soldiers on the front in Yugoslavia and Albania, he was dismayed by the Fascist regime's brutal imperialism in Dalmatia, Slovenia, and Montenegro because he suspected it would impose impossible burdens on Italy by creating new enemies among the occupied peoples that Italy would be forced to fight.^[112] Victor Emmanuel was disappointed with the Italian military's performance in the war, as he noted the army, navy, and air force could not drop their mutual jealousies and competition to work together.^[112] Furthermore, he feared that overly ambitious generals attempting to win promotion were attempting to persuade Mussolini to divert military resources in an ever-widening field of action.^[112] In June 1941, Mussolini's decision to follow Germany by waging war on the Soviet Union in which Victor Emmanuel was informed at the last moment giving him time only to advise to Mussolini against sending anything more than a token force to fight against the Soviet Union; his advice was not taken.^[112] A few weeks after Italy's declaration of war against the Soviet Union, a senior general of the Carabinieri informed the royal palace that the military police were awaiting a royal order to act against the Fascist regime.^[112] In September 1941, Victor Emmanuel held a private discussion with Ciano, in which Ciano said to the King that Fascism was doomed.^[112] In 1942, opposition to Italy's involvement in the war expanded among the Fascist regime's senior officials, with Giuseppe Bottai in private stating that he and other Fascist officials should have resigned from office when Mussolini declared war on Britain and France in June 1940, while Dino Grandi approached the King urging him to dismantle Mussolini's dictatorship in order to withdraw Italy from the war as he saw Italy facing ruin.^[113] By January 1943, King Victor Emmanuel III was persuaded by the Minister of the Royal Household, the Duke of Acquarone that Mussolini had to be removed from office.^[114]

In March 1943, the first sign of serious rebellion by Italians against the Fascist regime and the war began with a strike by factory workers who were joined by soldiers singing communist songs and even rank-in-file Fascist party members.^[113] The Fascist regime also faced passive resistance by civil servants who had begun to refuse to obey orders or pretend to obey orders.^[113]

On 25 July 1943, following the Allied invasion of Sicily, King Victor Emmanuel III dismissed Mussolini, placed him under arrest, and began secret negotiations with the Western Allies. An armistice was signed on 8 September 1943. On 12 September 1943, Mussolini was rescued by the Germans in Operation Oak and placed in charge of a puppet state called the Italian Social Republic (Repubblica Sociale Italiana/RSI, or Repubblica di Salò) in northern Italy. The Allies organized some Italian troops in the south into the Italian Co-belligerent Army, which fought alongside the Allies for the rest of the war, while other Italian troops, loyal to Mussolini and his RSI, continued to fight alongside the Germans in the National Republican Army. The Italian Civil War went on for months as the Allies, the Italian Co-Belligerent Army and the partisans contended the Social Republic's forces and its German allies. Some areas in Northern Italy were liberated from the Germans as late as May, 1945. Mussolini was killed by Communist partisans on 28 April 1945 while trying to escape to Switzerland.^[115]

The Dodecanese Islands were an Italian dependency from 1912 to 1947.

Montenegro was an Italian dependency from 1941 to 1943 known as the Governorate of Montenegro that was under the control of an Italian military governor. Initially, the Italians were not happy about it because of intended that Montenegro would become an "independent" state closely allied with Italy, reinforced through the strong dynastic links between Italy and Montenegro, as Queen Elena of Italy was a daughter of the last Montenegrin king Nicholas I. The Italian-backed Montenegrin nationalist Sekula Drljević and his followers attempted to create a Montenegrin state. On 12 July 1941, they proclaimed the "Kingdom of Montenegro" under the protection of Italy. In less than 24 hours, that triggered a general uprising against the Italians. Within three weeks, the insurgents managed to capture almost all the territory of Montenegro. Over 70,000 Italian troops and 20,000 of Albanian and Muslim irregulars were deployed to suppress the rebellion. Drljevic was expelled from Montenegro in October 1941. Montenegro then came under full direct Italian control. With the Italian capitulation of 1943, Montenegro came directly under the control of Germany.

Albania was an Italian protectorate and dependency from 1939 to 1943. In spite of Albania's long-standing protection and alliance with Italy, on 7 April 1939 Italian troops invaded Albania, five months before the start of the Second World War. Following the invasion, Albania became a protectorate under Italy, with King Victor Emmanuel III of Italy being awarded the crown of Albania. An Italian governor controlled Albania.^[116] Albanian troops under Italian control were sent to participate in the Italian invasion of Greece and the Axis occupation of Yugoslavia. Following Yugoslavia's defeat, Kosovo was annexed to Albania by the Italians.^[116]

Politically and economically dominated by Italy from its creation in 1913, Albania was occupied by Italian military forces in 1939 as the Albanian king Zog l fled the country with his family. The Albanian parliament voted to offer the Albanian throne to the King of Italy, resulting in a personal union between the two countries.^[116][117]

The Albanian army, having been trained by Italian advisors, was reinforced by 100,000 Italian troops. A Fascist militia was organized, drawing its strength principally from Albanians of Italian descent.

Albania served as the staging area for the Italian invasions of Greece and Yugoslavia. Albania annexed Kosovo in 1941 when Yugoslavia was dissolved, creating a Greater Albania.^[116]

Albanian troops were dispatched to the Eastern Front to fight the Soviets as part of the Italian Eighth Army.

Albania declared war on the United States in 1941.^[118]

When the Fascist regime of Italy fell, in September 1943 Albania fell under German occupation.

Italian East Africa was an Italian colony existing from 1936 to 1947. Prior to the invasion and annexation of Ethiopia into this united colony in 1936, Italy had two colonies, Eritrea and Somalia since the 1880s.

Libya was an Italian colony existing from 1911 to 1947. The northern portion of Libya was incorporated directly into Italy in 1939, however the region remained united as a colony under a colonial governor.

There was also a minor Italian concession territory in Tientsin, Republic of China.

The Japanese government justified its actions by claiming that it was seeking to unite East Asia under Japanese leadership in a Greater East Asia Co-Prosperity Sphere that would free East Asians from domination and rule by clients of Western powers.^[119] Japan invoked themes of Pan-Asianism and said that the Asian people needed to be free from Western influence.^[120]

The United States opposed the Japanese war in China, and recognized Chiang Kai-Shek's Nationalist Government as the legitimate government of China. As a result, the United States sought to bring the Japanese war effort to a halt by imposing an embargo on all trade between the United States and Japan. Japan was dependent on the United States for 80 percent of its petroleum, and as a consequence the embargo resulted in an economic and military crisis for Japan, because Japan could not continue its war effort against China without access to petroleum.^[121]

In order to maintain its military campaign in China despite its major loss of petroleum trade with the United States, Japan saw the best means to secure an alternative source of petroleum in the petroleum-rich and natural-resources-rich region of Southeast Asia.^[122] This threat of retaliation by Japan to the total trade embargo by the United States was known by the American government, including American Secretary of State Cordell Hull who was negotiating with the Japanese to avoid a war, fearing that the total embargo would pre-empt a Japanese attack on the Dutch East Indies.^[123]

Japan identified the American Pacific fleet based in Pearl Harbor as the principal threat to its designs to invade and capture Southeast Asia.^[122] Thus Japan initiated the attack on Pearl Harbor on 7 December 1941 as a means to inhibit an American response to the invasion of Southeast Asia, and buy time to allow Japan to consolidate itself with these resources to engage in a total war against the United States, and force the United States to accept Japan's acquisitions.^[122] On 7 December 1941 Japan declared war on the United States and the British Empire.

The Empire of Japan, a constitutional monarchy ruled by Hirohito, was the principal Axis power in Asia and the Pacific. Under the emperor were a political cabinet and the Imperial General Headquarters, with two chiefs of staff. By 1945 the Emperor of Japan was more than a symbolic leader; he played a major role in devising a strategy to keep himself on the throne.^[124]

At its peak, Japan's Greater East Asia Co-Prosperity Sphere included Manchuria, Inner Mongolia, large parts of China, Malaysia, French Indochina, Dutch East Indies, The Philippines, Burma, a small part of India, and various Pacific Islands in the central Pacific.

As a result of the internal discord and economic downturn of the 1920s, militaristic elements set Japan on a path of expansionism. As the Japanese home islands lacked natural resources needed for growth, Japan planned to establish hegemony in Asia and become self-sufficient by acquiring territories with abundant natural resources. Japan's expansionist policies alienated it from other countries in the League of Nations and by the mid-1930s brought it closer to Germany and Italy, who had both pursued similar expansionist policies. Cooperation between Japan and Germany began with the Anti-Comintern Pact, in which the two countries agreed to ally to challenge any attack by the Soviet Union.

Japan entered into conflict against the Chinese in 1937. The Japanese invasion and occupation of parts of China resulted in numerous atrocities against civilians, such as the Nanking massacre and the Three Alls Policy. The Japanese also fought skirmishes with Soviet–Mongolian forces in Manchukuo in 1938 and 1939. Japan sought to avoid war with the Soviet Union by signing a non-aggression pact with it in 1941.

Japan's military leaders were divided on diplomatic relationships with Germany and Italy and the attitude towards the United States. The Imperial Japanese Army was in favour of war with the United States, but the Imperial Japanese Navy was generally strongly opposed. When Prime Minister of Japan General Hideki Tojo refused American demands that Japan withdraw its military forces from China, a confrontation became more likely.^[125] War with the United States was being discussed within the Japanese government by 1940.^[126] Commander of the Combined Fleet Admiral Isoroku Yamamoto was outspoken in his opposition, especially after the signing of the Tripartite Pact, saying on 14 October 1940: "To fight the United States is like fighting the whole world. But it has been decided. So I will fight the best I can. Doubtless I shall die on board Nagato [his flagship]. Meanwhile Tokyo will be burnt to the ground three times. Konoe and others will be torn to pieces by the revengeful people, I [shouldn't] wonder. "^[126] In October and November 1940, Yamamoto communicated with Navy Minister Oikawa, and stated, "Unlike the pre-Tripartite days, great determination is required to make certain that we avoid the danger of going to war. "^[126]

With the European powers focused on the war in Europe, Japan sought to acquire their colonies. In 1940 Japan responded to the German invasion of France by occupying French Indochina. The Vichy France regime, a de facto ally of Germany, accepted the takeover. The allied forces did not respond with war. However, the United States instituted an embargo against Japan in 1941 because of the continuing war in China. This cut off Japan's supply of scrap metal and oil needed for industry, trade, and the war effort.

To isolate the US forces stationed in the Philippines and to reduce US naval power, the Imperial General Headquarters ordered an attack on the US naval base at Pearl Harbor, Hawaii, on 7 December 1941. ^{[Comment 1] [127]} They also invaded Malaya and Hong Kong. Initially achieving a series of victories, by 1943 the Japanese forces were driven back towards the home islands. The Pacific War lasted until the atomic bombings of Hiroshima and Nagasaki in 1945. The Soviets formally declared war in August 1945 and engaged Japanese forces in Manchuria and northeast China.

Taiwan, then known as Formosa, was a Japanese dependency established in 1895.

Korea was a Japanese protectorate and dependency formally established by the Japan–Korea Treaty of 1910.

The South Pacific Mandate were territories granted to Japan in 1919 in the peace agreements of World War I, that designated to Japan the German South Pacific islands. Japan received these as a reward by the Allies of World War I, when Japan was then allied against Germany.

Japan occupied the Dutch East Indies during the war. Japan planned to transform these territories into a client state of Indonesia and sought alliance with Indonesian nationalists including future Indonesian President Sukarno, however these efforts did not deliver the creation of an Indonesian state until after Japan's surrender.^[128]

In addition to the 3 major Axis powers, 4 more countries and 2 puppet regimes signed the Tri-Partite Pact as its member states. Of the 4 countries, Romania, Hungary and Bulgaria participated in various Axis military operations with their national armed forces, while the 4th, Yugoslavia, saw its pro-Nazi government overthrown in a coup merely days after it signed the Pact, and the membership was reversed.

The 2 puppet regimes that signed the Tri-Partite Pact, Tiso-led Slovakia and the Independent State of Croatia are listed among the client states section below.

The Kingdom of Bulgaria was ruled by Тsar Boris III when it signed the Tripartite Pact on 1 March 1941. Bulgaria had been on the losing side in the First World War and sought a return of lost ethnically and historically Bulgarian territories, specifically in Macedonia and Thrace (all within Kingdom of Yugoslavia, Kingdom of Greece and Turkey). During the 1930s, because of traditional right-wing elements, Bulgaria drew closer to Nazi Germany. In 1940 Germany pressured Romania to sign the Treaty of Craiova, returning to Bulgaria the region of Southern Dobrudja, which it had lost in 1913. The Germans also promised Bulgaria — if it joined the Axis — an enlargement of its territory to the borders specified in the Treaty of San Stefano.

Bulgaria participated in the Axis invasion of Yugoslavia and Greece by letting German troops attack from its territory and sent troops to Greece on April 20. As a reward, the Axis powers allowed Bulgaria to occupy parts of both countries—southern and south-eastern Yugoslavia (Vardar Banovina) and north-eastern Greece (parts of Greek Macedonia and Greek Thrace). The Bulgarian forces in these areas spent the following years fighting various nationalist groups and resistance movements. Despite German pressure, Bulgaria did not take part in the Axis invasion of the Soviet Union and actually never declared war on the Soviet Union. The Bulgarian Navy was nonetheless involved in a number of skirmishes with the Soviet Black Sea Fleet, which attacked Bulgarian shipping.

Following the Japanese attack on Pearl Harbor in December 1941, the Bulgarian government declared war on the Western Allies. This action remained largely symbolic (at least from the Bulgarian perspective), until August 1943, when Bulgarian air defense and air force attacked Allied bombers, returning (heavily damaged) from a mission over the Romanian oil refineries. This turned into a disaster for the citizens of Sofia and other major Bulgarian cities, which were heavily bombed by the Allies in the winter of 1943–1944.

Bulgaria left the Axis on 17 August 1944, when it declared strict neutrality, repudiated the previous wartime policies, granted amnesty to all political prisoners and repealed all anti-Jewish legislation. However, on 30 August, the Soviet Government announced that it refused to recognize Bulgaria's recently proclaimed neutrality.^{[129][130][131]}

On 2 September 1944, as the Red Army approached the Bulgarian border, a new Bulgarian government came to power and expelled the few remaining German troops. However, the Soviet Union declared war on Bulgaria on 5 September, and on 8 September the Red Army marched into the country, meeting no resistance. This was followed by the coup d'état of 9 September 1944, which brought a government of the pro-Soviet Fatherland Front to power. After this, the Bulgarian army (as part of the Red Army's 3rd Ukrainian Front) fought the Germans in Yugoslavia and Hungary, sustaining numerous casualties. Despite this, the Paris Peace Treaty treated Bulgaria as one of the defeated countries. Bulgaria was allowed to keep Southern Dobruja, but had to give up all claims to Greek and Yugoslav territory.

Hungary, ruled by Regent Admiral Miklós Horthy, was the first country apart from Germany, Italy, and Japan to adhere to the Tripartite Pact, signing the agreement on 20 November 1940. Slovakia had been a client state of Germany since 1939.^[132]

Political instability plagued the country until Miklós Horthy, a Hungarian nobleman and Austro-Hungarian naval officer, became regent in 1920. The vast majority of the Hungarians desired to recover territories lost through the Trianon Treaty. The country drew closer to Germany and Italy largely because of a shared desire to revise the peace settlements made after World War I.^[133] Many people sympathized with the anti-Semitic policy of the Nazi regime. Due to its supportive stance towards Germany and the new efforts in the international policy, Hungary gained favourable territorial settlements by the First Vienna Award, after the breakup of Czechoslovakia occupied and annexed the remainder of Carpathian Ruthenia and in 1940 received Northern Transylvania from Romania via the Second Vienna Award. Hungarians permitted German troops to transit through their territory during the invasion of Yugoslavia, and Hungarian forces took part in the invasion. Parts of Yugoslavia were annexed to Hungary; the United Kingdom immediately broke off diplomatic relations in response.

Although Hungary did not initially participate in the German invasion of the Soviet Union, Hungary and the Soviet Union became belligerents on 27 June 1941. Over 500,000 soldiers served on the Eastern Front. All five of Hungary's field armies ultimately participated in the war against the Soviet Union; a significant contribution was made by the Hungarian Second Army.

On 25 November 1941, Hungary was one of thirteen signatories to the revived Anti-Comintern Pact. Hungarian troops, like their Axis counterparts, were involved in numerous actions against the Soviets. By the end of 1943, the Soviets had gained the upper hand and the Germans were retreating. The Hungarian Second Army was destroyed in fighting on the Voronezh Front, on the banks of the Don River. In 1944, with Soviet troops advancing toward Hungary, Horthy attempted to reach an armistice with the Allies. However, the Germans replaced the existing regime with a new one. After fierce fighting, Budapest was taken by the Soviets. A number of pro-German Hungarians retreated to Italy and Germany, where they fought until the end of the war.

Relations between Germany and the regency of Miklós Horthy collapsed in 1944 when Horthy attempted to negotiate a peace agreement with the Soviets and jump out of the war without German approval. Horthy was forced to abdicate after German commandos, led by Colonel Otto Skorzeny, held his son hostage as part of Operation Panzerfaust.

Hungary was reorganized following Horthy's abdication in December 1944 into a totalitarian fascist regime called the Government of National Unity, led by Ferenc Szálasi. He had been Prime Minister of Hungary since October 1944 and was leader of the anti-Semitic fascist Arrow Cross Party. In power, his government was a puppet regime with little authority, and the country was effectively under German control. Days after the Szálasi government took power, the capital of Budapest was surrounded by the Soviet Red Army. German and Hungarian fascist forces tried to hold off the Soviet advance but failed. In March 1945, Szálasi fled to Germany as the leader of a government in exile, until the surrender of Germany in May 1945.

When war erupted in Europe in 1939, the Kingdom of Romania was pro-British and allied to the Poles. Following the invasion of Poland by Germany and the Soviet Union, and the German conquest of France and the Low Countries, Romania found itself increasingly isolated; meanwhile, pro-German and pro-Fascist elements began to grow.

The August 1939 Molotov–Ribbentrop Pact between Germany and the Soviet Union contained a secret protocol ceding Bessarabia, and Northern Bukovina to the Soviet Union.^[73] On June 28, 1940, the Soviet Union occupied and annexed Bessarabia, as well as part of northern Romania and the Hertza region.^[134] On 30 August 1940, as a result of the German-Italian arbitrated Second Vienna Award Romania had to cede Northern Transylvania to Hungary. Southern Dobruja was ceded to Bulgaria in September 1940. In an effort to appease the Fascist elements within the country and obtain German protection, King Carol II appointed the General Ion Antonescu as Prime Minister on September 6, 1940.

Two days later, Antonescu forced the king to abdicate and installed the king's young son Michael (Mihai) on the throne, then declared himself Conducător ("Leader") with dictatorial powers. The National Legionary State was proclaimed on 14 September, with the Iron Guard ruling together with Antonescu as the sole legal political movement in Romania. Under King Michael I and the military government of Antonescu, Romania signed the Tripartite Pact on November 23, 1940. German troops entered the country on 10 October 1941, officially to train the Romanian Army. Hitler's directive to the troops on 10 October had stated that "it is necessary to avoid even the slightest semblance of military occupation of Romania".^[135] The entrance of German troops in Romania determined Italian dictator Benito Mussolini to launch an invasion of Greece, starting the Greco-Italian War.^[136] Having secured Hitler's approval in January 1941, Antonescu ousted the Iron Guard from power.

Romania was subsequently used as a platform for invasions of Yugoslavia and the Soviet Union. Despite not being involved militarily in the Invasion of Yugoslavia, Romania requested that Hungarian troops not operate in the Banat. Paulus thus modified the Hungarian plan and kept their troops west of the Tisza.^[137]

Romania's military industry was small but versatile, able to copy and produce thousands of French and Soviet mortars, hundreds of German 37 mm anti-aircraft guns, 200 British Vickers Model 1931 75 mm anti-aircraft guns, hundreds of French 47 mm anti-tank guns, thousands of Czechoslovak machine guns and 126 French Renault UE armored tractors. Original products include the Orița M1941 sub-machinegun, the 75 mm Reșița Model 1943 anti-tank gun with a muzzle velocity of over 1 km/second of which up to 400 were made and about a hundred tank destroyers, the most notable being the Mareșal tank destroyer, which is credited with being the inspiration for the German Hetzer.^[138] Romania also built sizable warships, such as the minelayer Amiral Murgescu and the submarines Rechinul and Marsuinul. Hundreds of originally-designed aircraft were also produced, such as the fighter IAR-80 and the light bomber IAR-37. Romania had also been a major power in the oil industry since the 1800s. It was one of the largest producers in Europe and the Ploiești oil refineries provided about 30% of all Axis oil production.^[139]

Romania joined the German-led invasion of the Soviet Union on June 22, 1941. Antonescu was the only foreign leader Hitler consulted on military matters^[140] and the two would meet no less than ten times throughout the war.^[141] Romania re-captured Bessarabia and Northern Bukovina during Operation Munchen before conquering further Soviet territory and establishing the Transnistria Governorate. After the Siege of Odessa, the city became the capital of the Governorate. Romanian troops fought their way into the Crimea alongside German troops and contributed significantly to the Siege of Sevastopol. Later, Romanian mountain troops joined the German campaign in the Caucasus, reaching as far as Nalchik.^[142] After suffering devastating losses at Stalingrad, Romanian officials began secretly negotiating peace conditions with the Allies. By 1943, the tide began to turn. The Soviets pushed further west, retaking Ukraine and eventually launching an unsuccessful invasion of eastern Romania in the spring of 1944. Romanian troops in the Crimea helped repulse initial Soviet landings, but eventually all of the peninsula was re-conquered by Soviet forces and the Romanian Navy evacuated over 100,000 German and Romanian troops, an achievement which earned Romanian Admiral Horia Macellariu the Knight's Cross of the Iron Cross.^[143] During the Jassy-Kishinev Offensive of August 1944, Romania switched sides on August 23, 1944. Romanian troops then fought alongside the Soviet Army until the end of the war, reaching as far as Czechoslovakia and Austria.

After the surrender of Italy in September 1943, Romania attained the status of second Axis power in Europe.^[144]

The British historian Dennis Deletant has asserted that, Romania's crucial contributions to the Axis war effort, including having the third largest Axis army in Europe and sustaining the German war effort through oil and other materiel, meant that it was "on a par with Italy as a principal ally of Germany and not in the category of a minor Axis satellite".^[145]

Yugoslavia was largely surrounded by members of the pact and now bordered the German Reich. From late 1940 Hitler sought a non-aggression pact with Yugoslavia. In February 1941, Hitler called for Yugoslavia's accession to the Tripartite Pact, the Yugoslav delayed. In March, divisions of the German army arrived at the Bulgarian-Yugoslav border and permission was sought for them to pass through to attack Greece. On 25 March 1941, fearing that Yugoslavia would be invaded otherwise, the Yugoslav government signed the Tripartite Pact with significant reservations. Unlike other Axis powers, Yugoslavia was not obliged to provide military assistance, nor to provide its territory for Axis to move military forces during the war. Less than two days later, after demonstrations in the streets of Belgrade, Prince Paul and the government were removed from office by a coup d'état. Seventeen-year-old King Peter was declared to be of age. The new Yugoslav government under General Dušan Simović, refused to ratify Yugoslavia's signing of the Tripartite Pact, and started negotiations with Great Britain and Soviet Union. Winston Churchill commented that "Yugoslavia has found its soul"; however, Hitler invaded and quickly took control.

Various countries fought side by side with the Axis powers for a common cause. These countries were not signatories of the Tripartite Pact and thus not formal members of the Axis.

Although Finland never signed the Tripartite Pact and legally (de jure) was not a part of the Axis, it was Axis-aligned in its fight against the Soviet Union.^[146] Finland signed the revived Anti-Comintern Pact of November 1941.^[147]

The August 1939 Molotov–Ribbentrop Pact between Germany and the Soviet Union contained a secret protocol dividing much of eastern Europe and assigning Finland to the Soviet sphere of influence.^[73][148] After unsuccessfully attempting to force territorial and other concessions on the Finns, the Soviet Union tried to invade Finland in November 1939 during the Winter War, intending to establish a communist puppet government in Finland.^[149][150] The conflict threatened Germany's iron-ore supplies and offered the prospect of Allied interference in the region.^[151] Despite Finnish resistance, a peace treaty was signed in March 1940, wherein Finland ceded some key territory to the Soviet Union, including the Karelian Isthmus, containing Finland's second-largest city, Viipuri, and the critical defensive structure of the Mannerheim Line. After this war, Finland sought protection and support from the United Kingdom^[152][153] and non-aligned Sweden,^[154] but was thwarted by Soviet and German actions. This resulted in Finland being drawn closer to Germany, first with the intent of enlisting German support as a counterweight to thwart continuing Soviet pressure, and later to help regain lost territories.

In the opening days of Operation Barbarossa, Germany's invasion of the Soviet Union, Finland permitted German planes returning from mine dropping runs over Kronstadt and Neva River to refuel at Finnish airfields before returning to bases in East Prussia. In retaliation, the Soviet Union launched a major air offensive against Finnish airfields and towns, which resulted in a Finnish declaration of war against the Soviet Union on 25 June 1941. The Finnish conflict with the Soviet Union is generally referred to as the Continuation War.

Finland's main objective was to regain territory lost to the Soviet Union in the Winter War. However, on 10 July 1941, Field Marshal Carl Gustaf Emil Mannerheim issued an Order of the Day that contained a formulation understood internationally as a Finnish territorial interest in Russian Karelia.

Diplomatic relations between the United Kingdom and Finland were severed on 1 August 1941, after the British bombed German forces in the Finnish village and port of Petsamo. The United Kingdom repeatedly called on Finland to cease its offensive against the Soviet Union, and declared war on Finland on 6 December 1941, although no other military operations followed. War was never declared between Finland and the United States, though relations were severed between the two countries in 1944 as a result of the Ryti-Ribbentrop Agreement.

Finland maintained command of its armed forces and pursued war objectives independently of Germany. Germans and Finns did work closely together during Operation Silverfox, a joint offensive against Murmansk. Finland refused German requests to participate actively in the Siege of Leningrad, and also granted asylum to Jews, while Jewish soldiers continued to serve in its army.

The relationship between Finland and Germany more closely resembled an alliance during the six weeks of the Ryti-Ribbentrop Agreement, which was presented as a German condition for help with munitions and air support, as the Soviet offensive coordinated with D-Day threatened Finland with complete occupation. The agreement, signed by President Risto Ryti but never ratified by the Finnish Parliament, bound Finland not to seek a separate peace.

After Soviet offensives were fought to a standstill, Ryti's successor as president, Marshall Mannerheim, dismissed the agreement and opened secret negotiations with the Soviets, which resulted in a ceasefire on 4 September and the Moscow Armistice on 19 September 1944. Under the terms of the armistice, Finland was obliged to expel German troops from Finnish territory, which resulted in the Lapland War. Finland signed a peace treaty with the Allied powers in 1947.

The Free City of Danzig, a semi-autonomous city-state under League of Nations protection, briefly aided the Nazis at the beginning of the invasion of Poland, attacking Polish territories bordering the city. The Free City of Danzig Police and militia fought with German soldiers during the Battle of Westerplatte and the attack on the Polish post office in Danzig.^[155] After the end of the Polish campaign, Danzig was annexed into Germany.

The Kingdom of Iraq was briefly an ally of the Axis, fighting the United Kingdom in the Anglo-Iraqi War of May 1941.

Anti-British sentiments were widespread in Iraq prior to 1941. Seizing power on 1 April 1941, the nationalist government of Prime Minister Rashid Ali repudiated the Anglo-Iraqi Treaty of 1930 and demanded that the British abandon their military bases and withdraw from the country. Ali sought support from Germany and Italy in expelling British forces from Iraq.

On 9 May 1941, Mohammad Amin al-Husayni, the Mufti of Jerusalem and associate of Ali, declared holy war^[156] against the British and called on Arabs throughout the Middle East to rise up against British rule. On 25 May 1941, the Germans stepped up offensive operations in the Middle East.

Hitler issued Order 30: "The Arab Freedom Movement in the Middle East is our natural ally against England. In this connection special importance is attached to the liberation of Iraq ... I have therefore decided to move forward in the Middle East by supporting Iraq. "^[157]

Hostilities between the Iraqi and British forces began on 2 May 1941, with heavy fighting at the RAF air base in Habbaniyah. The Germans and Italians dispatched aircraft and aircrew to Iraq utilizing Vichy French bases in Syria, which would later invoke fighting between Allied and Vichy French forces in Syria.

The Germans planned to coordinate a combined German-Italian offensive against the British in Egypt, Palestine, and Iraq. Iraqi military resistance ended by 31 May 1941. Rashid Ali and the Mufti of Jerusalem fled to Iran, then Turkey, Italy, and finally Germany, where Ali was welcomed by Hitler as head of the Iraqi government-in-exile in Berlin. In propaganda broadcasts from Berlin, the Mufti continued to call on Arabs to rise up against the British and aid German and Italian forces. He also helped recruit Muslim volunteers in the Balkans for the Waffen-SS.

Thailand waged the Franco-Thai War in October 1940 to May 1941 to reclaim territory from French Indochina. It became a formal ally of Japan from 25 January 1942. Japanese forces invaded Thailand's territory an hour and a half before the attack on Pearl Harbor (because of the International Dateline, the local time was on the morning of 8 December 1941). Only hours after the invasion, Prime Minister Field Marshal Phibunsongkhram ordered the cessation of resistance against the Japanese. On 21 December 1941, a military alliance with Japan was signed and on 25 January 1942, Sang Phathanothai read over the radio Thailand's formal declaration of war on the United Kingdom and the United States. The Thai ambassador to the United States, Mom Rajawongse Seni Pramoj, did not deliver his copy of the declaration of war. Therefore, although the British reciprocated by declaring war on Thailand and considered it a hostile country, the United States did not.

The Thais and Japanese agreed that Shan State and Kayah State were to be under Thai control. The rest of Burma was to be under Japanese control. On 10 May 1942, the Thai Phayap Army entered Burma's eastern Shan State, which had been claimed by Siamese kingdoms. Three Thai infantry and one cavalry division, spearheaded by armoured reconnaissance groups and supported by the air force, engaged the retreating Chinese 93rd Division. Kengtung, the main objective, was captured on 27 May. Renewed offensives in June and November saw the Chinese retreat into Yunnan.^[158] The area containing the Shan States and Kayah State was annexed by Thailand in 1942. The areas were ceded back to Burma in 1945.

The Free Thai Movement ("Seri Thai") was established during these first few months. Parallel Free Thai organizations were also established in the United Kingdom. Queen Rambai Barni was the nominal head of the British-based organization, and Pridi Banomyong, the regent, headed its largest contingent, which was operating within Thailand. Aided by elements of the military, secret airfields and training camps were established, while Office of Strategic Services and Force 136 agents slipped in and out of the country.

As the war dragged on, the Thai population came to resent the Japanese presence. In June 1944, Phibun was overthrown in a coup d'état. The new civilian government under Khuang Aphaiwong attempted to aid the resistance while maintaining cordial relations with the Japanese. After the war, U. S. influence prevented Thailand from being treated as an Axis country, but the British demanded three million tons of rice as reparations and the return of areas annexed from Malaya during the war. Thailand also returned the portions of British Burma and French Indochina that had been annexed. Phibun and a number of his associates were put on trial on charges of having committed war crimes and of collaborating with the Axis powers. However, the charges were dropped due to intense public pressure. Public opinion was favorable to Phibun, as he was thought to have done his best to protect Thai interests.

The collaborationist administrations of German-occupied countries in Europe had varying degrees of autonomy, and not all of them qualified as fully recognized sovereign states. The General Government in occupied Poland was a German administration, not a Polish government. In occupied Norway, the National Government headed by Vidkun Quisling – whose name came to symbolize pro-Axis collaboration in several languages – was subordinate to the Reichskommissariat Norwegen. It was never allowed to have any armed forces, be a recognized military partner, or have autonomy of any kind. In the occupied Netherlands, Anton Mussert was given the symbolic title of "Führer of the Netherlands' people". His National Socialist Movement formed a cabinet assisting the German administration, but was never recognized as a real Dutch government. The following list of German client states includes only those entities that were officially considered to be independent countries allied with Germany. They were under varying degrees of German influence and control, but were not ruled directly by Germans.

After the Italian armistice, a vacuum of power opened up in Albania. The Italian occupying forces were rendered largely powerless, as the National Liberation Movement took control of the south and the National Front (Balli Kombëtar) took control of the north. Albanians in the Italian army joined the guerrilla forces. In September 1943 the guerrillas moved to take the capital of Tirana, but German paratroopers dropped into the city. Soon after the battle, the German High Command announced that they would recognize the independence of a greater Albania. They organized an Albanian government, police, and military in collaboration with the Balli Kombëtar. The Germans did not exert heavy control over Albania's administration, but instead attempted to gain popular appeal by giving their political partners what they wanted. Several Balli Kombëtar leaders held positions in the regime. The joint forces incorporated Kosovo, western Macedonia, southern Montenegro, and Presevo into the Albanian state. A High Council of Regency was created to carry out the functions of a head of state, while the government was headed mainly by Albanian conservative politicians. Albania was the only European country occupied by the Axis powers that ended World War II with a larger Jewish population than before the war.^[159] The Albanian government had refused to hand over their Jewish population. They provided Jewish families with forged documents and helped them disperse in the Albanian population.^[160] Albania was completely liberated on November 29, 1944.

The Government of National Salvation, also referred to as the Nedić regime, was the second Serbian puppet government, after the Commissioner Government, established on the Territory of the (German) Military Commander in Serbia^[3] during World War II. It was appointed by the German Military Commander in Serbia and operated from 29 August 1941 to October 1944. The Serbian puppet state enjoyed significant support.^[162] The Prime Minister throughout was General Milan Nedić. The Government of National Salvation was evacuated from Belgrade to Kitzbühel, Germany in the first week of October 1944 before the German withdrawal from Serbia was complete.

Racial laws were introduced in all occupied territories with immediate effects on Jews and Roma people, as well as causing the imprisonment of those opposed to Nazism. Several concentration camps were formed in Serbia and at the 1942 Anti-Freemason Exhibition in Belgrade the city was pronounced to be free of Jews (Judenfrei). On 1 April 1942, a Serbian Gestapo was formed. An estimated 120,000 people were interned in German-run concentration camps in Nedić's Serbia between 1941 and 1944. 50,000 to 80,000 were killed during this period. Serbia became the second country in Europe, following Estonia, to be proclaimed Judenfrei (free of Jews). Approximately 14,500 Serbian Jews – 90 percent of Serbia's Jewish population of 16,000 – were murdered in World War II.

Collaborationist armed formations forces were involved, either directly or indirectly, in the mass killings of Jews, Roma and those Serbs who sided with any anti-German resistance or were suspects of being a member of such. These forces were also responsible for the killings of many Croats and Muslims; however, some Croats who took refuge in Nedić's Serbia were not discriminated against. After the war, the Serbian involvement in many of these events and the issue of Serbian collaboration were subject to historical revisionism by later public figures.

Nedić himself was captured by the Americans when they occupied the former territory of Austria, and was subsequently handed over to the Yugoslav communist authorities to act as a witness against war criminals, on the understanding he would be returned to American custody to face trial by the Allies. The Yugoslav authorities refused to return Nedić to United States custody. He died on 4 February 1946 after either jumping or falling out of the window of a Belgrade hospital, under circumstances which remain unclear.

Italian Fascist leader Benito Mussolini formed the Italian Social Republic (Repubblica Sociale Italiana in Italian) on 23 September 1943, succeeding the Kingdom of Italy as a member of the Axis.

Mussolini had been removed from office and arrested by King Victor Emmanuel III on 25 July 1943. After the Italian armistice, in a raid led by German paratrooper Otto Skorzeny, Mussolini was rescued from arrest.

Once restored to power, Mussolini declared that Italy was a republic and that he was the new head of state. He was subject to German control for the duration of the war.

The Slovak Republic under President Josef Tiso signed the Tripartite Pact on 24 November 1940.

Slovakia had been closely aligned with Germany almost immediately from its declaration of independence from Czechoslovakia on 14 March 1939. Slovakia entered into a treaty of protection with Germany on 23 March 1939.

Slovak troops joined the German invasion of Poland, having interest in Spiš and Orava. Those two regions, along with Cieszyn Silesia, had been disputed between Poland and Czechoslovakia since 1918. The Poles fully annexed them following the Munich Agreement. After the invasion of Poland, Slovakia reclaimed control of those territories.

Slovakia invaded Poland alongside German forces, contributing 50,000 men at this stage of the war.

Slovakia declared war on the Soviet Union in 1941 and signed the revived Anti-Comintern Pact in 1941. Slovak troops fought on Germany's Eastern Front, furnishing Germany with two divisions totaling 80,000 men. Slovakia declared war on the United Kingdom and the United States in 1942.

Slovakia was spared German military occupation until the Slovak National Uprising, which began on 29 August 1944, and was almost immediately crushed by the Waffen SS and Slovak troops loyal to Josef Tiso.

After the war, Tiso was executed and Slovakia once again became part of Czechoslovakia. The border with Poland was shifted back to the pre-war state. Slovakia and the Czech Republic finally separated into independent states in 1993.

Italy occupied several nations and set up clients in those regions to carry out administrative tasks and maintain order.

The Principality of Monaco was officially neutral during the war. The population of the country was largely of Italian descent and sympathized with Italy. Its prince was a close friend of the Vichy French leader, Marshal Philippe Pétain, an Axis collaborator. A fascist regime was established under the nominal rule of the prince when the Italian Fourth Army occupied the country on November 10, 1942 as a part of Case Anton. Monaco's military forces, consisting primarily of police and palace guards, collaborated with the Italians during the occupation. German troops occupied Monaco in 1943, and Monaco was liberated by Allied forces in 1944.

On 10 April 1941, the Independent State of Croatia (Nezavisna Država Hrvatska, or NDH) declared itself a member of the Axis, co-signing the Tripartite Pact. The NDH remained a member of the Axis until the end of Second World War, its forces fighting for Germany even after its territory had been overrun by Yugoslav Partisans. On 16 April 1941, Ante Pavelić, a Croatian nationalist and one of the founders of the Ustaše ("Croatian Liberation Movement"), was proclaimed Poglavnik (leader) of the new regime.

Initially the Ustaše had been heavily influenced by Italy. They were actively supported by Mussolini's Fascist regime in Italy, which gave the movement training grounds to prepare for war against Yugoslavia, as well as accepting Pavelić as an exile and allowing him to reside in Rome. Italy intended to use the movement to destroy Yugoslavia, which would allow Italy to expand its power through the Adriatic. Hitler did not want to engage in a war in the Balkans until the Soviet Union was defeated. The Italian invasion of Greece was not going well; Mussolini wanted Germany to invade Yugoslavia to save the Italian forces that attacked the Greek border. Hitler reluctantly agreed; Yugoslavia was invaded and the Independent State of Croatia was created. Pavelić led a delegation to Rome and offered the crown of Croatia to an Italian prince of the House of Savoy, who was crowned Tomislav II, King of Croatia, Prince of Bosnia and Herzegovina, Voivode of Dalmatia, Tuzla and Knin, Prince of Cisterna and of Belriguardo, Marquess of Voghera, and Count of Ponderano. The next day, Pavelić signed the Contracts of Rome with Mussolini, ceding Dalmatia to Italy and fixing the permanent borders between the NDH and Italy. Italian armed forces were allowed to control all of the coastline of the NDH, effectively giving Italy total control of the Adriatic coastline.

However, strong German influence began to be asserted soon after the NDH was founded. When the King of Italy ousted Mussolini from power and Italy capitulated, the NDH became completely under German influence.

The platform of the Ustaše movement proclaimed that Croatians had been oppressed by the Serb-dominated Kingdom of Yugoslavia, and that Croatians deserved to have an independent nation after years of domination by foreign empires. The Ustaše perceived Serbs to be racially inferior to Croats and saw them as infiltrators who were occupying Croatian lands. They saw the extermination of Serbs as necessary to racially purify Croatia. While part of Yugoslavia, many Croatian nationalists violently opposed the Serb-dominated Yugoslav monarchy, and assassinated Alexander I of Yugoslavia, together with the Internal Macedonian Revolutionary Organization. The regime enjoyed support amongst radical Croatian nationalists. Ustashe forces fought against communist Yugoslav Partisan guerrilla throughout the war.

Upon coming to power, Pavelić formed the Croatian Home Guard (Hrvatsko domobranstvo) as the official military force of the NDH. Originally authorized at 16,000 men, it grew to a peak fighting force of 130,000. The Croatian Home Guard included an air force and navy, although its navy was restricted in size by the Contracts of Rome. In addition to the Croatian Home Guard, Pavelić was also the supreme commander of the Ustaše militia, although all NDH military units were generally under the command of the German or Italian formations in their area of operations.

The Ustaše government declared war on the Soviet Union, signed the Anti-Comintern Pact of 1941, and sent troops to Germany's Eastern Front. Ustaše militia were garrisoned in the Balkans, battling the communist partisans.

The Ustaše government applied racial laws on Serbs, Jews, Romani people, as well as targeting those opposed to the fascist regime, and after June 1941 deported them to the Jasenovac concentration camp or to German camps in Poland. The racial laws were enforced by the Ustaše militia. The exact number of victims of the Ustaše regime is uncertain due to the destruction of documents and varying numbers given by historians. According to the United States Holocaust Memorial Museum in Washington, DC, between 320,000 and 340,000 Serbs were killed in the NDH.^[163]

Following the German invasion of Greece and the flight of the Greek government to Crete and then Egypt, the Hellenic State was formed in May 1941 as a puppet state of both Italy and Germany. Initially, Italy had wished to annex Greece, but was pressured by Germany to avoid civil unrest such as had occurred in Bulgarian-annexed areas. The result was Italy accepting the creation of a puppet regime with the support of Germany. Italy had been assured by Hitler of a primary role in Greece. Most of the country was held by Italian forces, but strategic locations (Central Macedonia, the islands of the northeastern Aegean, most of Crete, and parts of Attica) were held by the Germans, who seized most of the country's economic assets and effectively controlled the collaborationist government. The puppet regime never commanded any real authority, and did not gain the allegiance of the people. It was somewhat successful in preventing secessionist movements like the Vlach "Roman Legion" from establishing themselves. By mid-1943, the Greek Resistance had liberated large parts of the mountainous interior ("Free Greece"), setting up a separate administration there. After the Italian armistice, the Italian occupation zone was taken over by the German armed forces, who remained in charge of the country until their withdrawal in autumn 1944. In some Aegean islands, German garrisons were left behind, and surrendered only after the end of the war.

The Empire of Japan created a number of client states in the areas occupied by its military, beginning with the creation of Manchukuo in 1932. These puppet states achieved varying degrees of international recognition.

The Japanese Army and Burma nationalists, led by Aung San, seized control of Burma from the United Kingdom during 1942. A State of Burma was formed on 1 August under the Burmese nationalist leader Ba Maw. The Ba Maw regime established the Burma Defence Army (later renamed the Burma National Army), which was commanded by Aung San.

The Kingdom of Cambodia was a short-lived Japanese puppet state that lasted from 9 March 1945 to 15 August 1945.

The Japanese entered Cambodia in mid-1941, but allowed Vichy French officials to remain in administrative posts. The Japanese calls for an "Asia for the Asiatics" won over many Cambodian nationalists.

This policy changed during the last months of the war. The Japanese wanted to gain local support, so they dissolved French colonial rule and pressured Cambodia to declare its independence within the Greater East Asia Co-Prosperity Sphere. Four days later, King Sihanouk declared Kampuchea (the original Khmer pronunciation of Cambodia) independent. Co-editor of the Nagaravatta, Son Ngoc Thanh, returned from Tokyo in May and was appointed foreign minister.

On the date of Japanese surrender, a new government was proclaimed with Son Ngoc Thanh as prime minister. When the Allies occupied Phnom Penh in October, Son Ngoc Thanh was arrested for collaborating with the Japanese and was exiled to France. Some of his supporters went to northwestern Cambodia, which had been under Thai control since the French-Thai War of 1940, where they banded together as one faction in the Khmer Issarak movement, originally formed with Thai encouragement in the 1940s.

During the Second Sino-Japanese War, Japan advanced from its bases in Manchuria to occupy much of East and Central China. Several Japanese puppet states were organized in areas occupied by the Japanese Army, including the Provisional Government of the Republic of China at Beijing, which was formed in 1937, and the Reformed Government of the Republic of China at Nanjing, which was formed in 1938. These governments were merged into the Reorganized National Government of China at Nanjing on 29 March 1940. Wang Jingwei became head of state. The government was to be run along the same lines as the Nationalist regime and adopted its symbols.

The Nanjing Government had no real power; its main role was to act as a propaganda tool for the Japanese. The Nanjing Government concluded agreements with Japan and Manchukuo, authorising Japanese occupation of China and recognising the independence of Manchukuo under Japanese protection. The Nanjing Government signed the Anti-Comintern Pact of 1941 and declared war on the United States and the United Kingdom on 9 January 1943.

The government had a strained relationship with the Japanese from the beginning. Wang's insistence on his regime being the true Nationalist government of China and in replicating all the symbols of the Kuomintang led to frequent conflicts with the Japanese, the most prominent being the issue of the regime's flag, which was identical to that of the Republic of China.

The worsening situation for Japan from 1943 onwards meant that the Nanking Army was given a more substantial role in the defence of occupied China than the Japanese had initially envisaged. The army was almost continuously employed against the communist New Fourth Army.

Wang Jingwei died on 10 November 1944, and was succeeded by his deputy, Chen Gongbo. Chen had little influence; the real power behind the regime was Zhou Fohai, the mayor of Shanghai. Wang's death dispelled what little legitimacy the regime had. The state stuttered on for another year and continued the display and show of a fascist regime.

On 9 September 1945, following the defeat of Japan, the area was surrendered to General He Yingqin, a nationalist general loyal to Chiang Kai-shek. The Nanking Army generals quickly declared their alliance to the Generalissimo, and were subsequently ordered to resist Communist attempts to fill the vacuum left by the Japanese surrender. Chen Gongbo was tried and executed in 1946.

The Arzi Hukumat-e-Azad Hind, the Provisional Government of Free India was a state that was recognized by nine Axis governments. It was led by Subhas Chandra Bose, an Indian nationalist who rejected Mohandas K. Gandhi's nonviolent methods for achieving independence. The First INA faltered after its leadership objected to being a propaganda tool for Japanese war aims, and the role of I Kikan. It was revived by the Indian Independence League with Japanese support in 1942 after the ex-PoWs and Indian civilians in South-east Asia agreed to participate in the INA venture on the condition it was led by Subhash Chandra Bose. Bose declared India's independence on October 21, 1943. The Indian National Army was committed as a part of the U Go Offensive. It played a largely marginal role in the battle, and suffered serious casualties and had to withdraw with the rest of Japanese forces after the siege of Imphal was broken. It was later committed to the defence of Burma against the Allied offensive. It suffered a large number of desertions in this latter part. The remaining troops of the INA maintained order in Rangoon after the withdrawal of Ba Maw's government. although The provisional government was given nominal control of the Andaman and Nicobar Islands from November 1943 to August 1945.

Mengjiang was a Japanese puppet state in Inner Mongolia. It was nominally ruled by Prince Demchugdongrub, a Mongol nobleman descended from Genghis Khan, but was in fact controlled by the Japanese military. Mengjiang's independence was proclaimed on 18 February 1936, following the Japanese occupation of the region.

The Inner Mongolians had several grievances against the central Chinese government in Nanking, including their policy of allowing unlimited migration of Han Chinese to the region. Several of the young princes of Inner Mongolia began to agitate for greater freedom from the central government, and it was through these men that Japanese saw their best chance of exploiting Pan-Mongol nationalism and eventually seizing control of Outer Mongolia from the Soviet Union.

Japan created Mengjiang to exploit tensions between ethnic Mongolians and the central government of China, which in theory ruled Inner Mongolia. When the various puppet governments of China were unified under the Wang Jingwei government in March 1940, Mengjiang retained its separate identity as an autonomous federation. Although under the firm control of the Japanese Imperial Army, which occupied its territory, Prince Demchugdongrub had his own independent army.

Mengjiang vanished in 1945 following Japan's defeat in World War II. As Soviet forces advanced into Inner Mongolia, they met limited resistance from small detachments of Mongolian cavalry, which, like the rest of the army, were quickly overwhelmed.

Fears of Thai irredentism led to the formation of the first Lao nationalist organization, the Movement for National Renovation, in January 1941. The group was led by Prince Phetxarāt and supported by local French officials, though not by the Vichy authorities in Hanoi. This group wrote the current Lao national anthem and designed the current Lao flag, while paradoxically pledging support for France. The country declared its independence in 1945.

The liberation of France in 1944, bringing Charles de Gaulle to power, meant the end of the alliance between Japan and the Vichy French administration in Indochina. The Japanese had no intention of allowing the Gaullists to take over, and in March 1945 they staged a military coup in Hanoi. Some French units fled over the mountains to Laos, pursued by the Japanese, who occupied Viang Chan in March 1945 and Luang Phrabāng in April. King Sīsavāngvong was detained by the Japanese, but his son Crown Prince Savāngvatthanā called on all Lao to assist the French, and many Lao died fighting against the Japanese occupiers.

Prince Phetxarāt opposed this position. He thought that Lao independence could be gained by siding with the Japanese, who made him Prime Minister of Luang Phrabāng, though not of Laos as a whole. The country was in chaos, and Phetxarāt's government had no real authority. Another Lao group, the Lao Sēri (Free Lao), received unofficial support from the Free Thai movement in the Isan region.

Manchukuo, in the northeast region of China, had been a Japanese puppet state in Manchuria since the 1930s. It was nominally ruled by Puyi, the last emperor of the Qing Dynasty, but was in fact controlled by the Japanese military, in particular the Kwantung Army. While Manchukuo ostensibly was a state for ethnic Manchus, the region had a Han Chinese majority.

Following the Japanese invasion of Manchuria in 1931, the independence of Manchukuo was proclaimed on 18 February 1932, with Puyi as head of state. He was proclaimed the Emperor of Manchukuo a year later. The new Manchu nation was recognized by 23 of the League of Nations' 80 members. Germany, Italy, and the Soviet Union were among the major powers who recognised Manchukuo. Other countries who recognized the State were the Dominican Republic, Costa Rica, El Salvador, and Vatican City. Manchukuo was also recognised by the other Japanese allies and puppet states, including Mengjiang, the Burmese government of Ba Maw, Thailand, the Wang Jingwei regime, and the Indian government of Subhas Chandra Bose. The League of Nations later declared in 1934 that Manchuria lawfully remained a part of China. This precipitated Japanese withdrawal from the League. The Manchukuoan state ceased to exist after the Soviet invasion of Manchuria in 1945.

After the surrender of the Filipino and American forces in Bataan Peninsula and Corregidor Island, the Japanese established a puppet state in the Philippines in 1942.^[164] The following year, the Philippine National Assembly declared the Philippines an independent Republic and elected José Laurel as its President.^[165] There was never widespread civilian support for the state, largely because of the general anti-Japanese sentiment stemming from atrocities committed by the Imperial Japanese Army.^[166] The Second Philippine Republic ended with Japanese surrender in 1945, and Laurel was arrested and charged with treason by the US government. He was granted amnesty by President Manuel Roxas, and remained active in politics, ultimately winning a seat in the post-war Senate.

The Empire of Vietnam was a short-lived Japanese puppet state that lasted from 11 March to 23 August 1945.

When the Japanese seized control of French Indochina, they allowed Vichy French administrators to remain in nominal control. This French rule ended on 9 March 1945, when the Japanese officially took control of the government. Soon after, Emperor Bảo Đại voided the 1884 treaty with France and Trần Trọng Kim, a historian, became prime minister.

The country suffered through the Vietnamese Famine of 1945.

States listed in this section were not officially members of the Axis, but at some point during the war engaged in cooperation with one or more Axis members on level that makes their neutrality disputable.

Denmark was occupied by Germany after April 1940 but never joined the Axis. On 31 May 1939, Denmark and Germany signed a treaty of non-aggression, which did not contain any military obligations for either party.^[167] On April 9, Germany attacked Scandinavia, and the speed of the German invasion of Denmark prevented King Christian X and the Danish government from going into exile. They had to accept "protection by the Reich" and the stationing of German forces in exchange for nominal independence. Denmark coordinated its foreign policy with Germany, extending diplomatic recognition to Axis collaborator and puppet regimes, and breaking diplomatic relations with the Allied governments-in-exile. Denmark broke diplomatic relations with the Soviet Union and signed the Anti-Comintern Pact in 1941.^[168] However the United States and Britain ignored Denmark and worked with Denmark's ambassadors when it came to dealings about using Iceland, Greenland, and the Danish merchant fleet against Germany.^[169][170]

In 1941 Danish Nazis set up the Frikorps Danmark. Thousands of volunteers fought and many died as part of the German Army on the Eastern Front. Denmark sold agricultural and industrial products to Germany and made loans for armaments and fortifications. The German presence in Denmark, including the construction of the Danish paid for part of the Atlantic Wall fortifications and was never reimbursed.

The Danish protectorate government lasted until 29 August 1943, when the cabinet resigned after the regularly scheduled and largely free election concluding the Folketing's current term. The Germans imposed martial law, and Danish collaboration continued on an administrative level, with the Danish bureaucracy functioning under German command. The Danish navy scuttled 32 of its larger ships; Germany seized 64 ships and later raised and refitted 15 of the sunken vessels.^[171][172] 13 warships escaped to Sweden and formed a Danish naval flotilla in exile. Sweden allowed formation of a Danish military brigade in exile; it did not see combat.^[173] The resistance movement was active in sabotage and issuing underground newspapers and blacklists of collaborators.^[174]

Relations between the Soviet Union and the major Axis powers were generally hostile before 1938. In the Spanish Civil War, the Soviet Union gave military aid to the Second Spanish Republic, against Spanish Nationalist forces, which were assisted by Germany and Italy. However, the Nationalist forces were victorious. The Soviets suffered another political defeat when their ally Czechoslovakia was partitioned and taken over by Germany in 1938–39. In 1938 and 1939, the USSR fought and defeated Japan in two separate border conflicts, at Lake Khasan and Khalkhin Gol. The latter was a major Soviet victory that led the Japanese Army to avoid war with the Soviets and instead call for expansion south.

In 1939 the Soviet Union considered forming an alliance with either Britain and France or with Germany.^[175][176] When negotiations with Britain and France failed, they turned to Germany and signed the Molotov–Ribbentrop Pact in August 1939. Germany was now freed from the risk of war with the Soviets, and was assured a supply of oil. This included a secret protocol whereby the independent countries of Poland, Finland, Estonia, Romania, Latvia and Lithuania were divided into spheres of interest of the parties.^[73] The Soviet Union had been forced to cede the Kresy (Western Belarus and Western Ukraine) to Poland after losing the Soviet-Polish War of 1919–1921, and the Soviet Union sought to re-annex those territories.^[61]

On 1 September, barely a week after the pact had been signed, Germany invaded Poland. The Soviet Union invaded Poland from the east on 17 September and on 28 September signed a secret treaty with Nazi Germany to arrange coordination of fighting against Polish resistance. The Soviets targeted intelligence, entrepreneurs, and officers, committing a string of atrocities that culminated in the Katyn massacre and mass relocation to the Gulag in Siberia.^[177]

Soon thereafter, the Soviet Union occupied the Baltic countries of Estonia, Latvia, and Lithuania,^[134][178] and annexed Bessarabia and Northern Bukovina from Romania. The Soviet Union attacked Finland on 30 November 1939, which started the Winter War.^[150] Finnish defences prevented an all-out invasion, resulting in an interim peace, but Finland was forced to cede strategically important border areas near Leningrad.

The Soviet Union provided material support to Germany in the war effort against Western Europe through a pair of commercial agreements, the first in 1939 and the second in 1940, which involved exports of raw materials (phosphates, chromium and iron ore, mineral oil, grain, cotton, and rubber). These and other export goods transported through Soviet and occupied Polish territories allowed Germany to circumvent the British naval blockade.

In October and November 1940, German-Soviet talks about the potential of joining the Axis took place in Berlin.^[179][180] Joseph Stalin later personally countered with a separate proposal in a letter on 25 November that contained several secret protocols, including that "the area south of Batum and Baku in the general direction of the Persian Gulf is recognized as the center of aspirations of the Soviet Union", referring to an area approximating present day Iraq and Iran, and a Soviet claim to Bulgaria.^[180][181] Hitler never responded to Stalin's letter.^[182][183] Shortly thereafter, Hitler issued a secret directive on the invasion of the Soviet Union.^[181][184]

Germany ended the Molotov–Ribbentrop Pact by invading the Soviet Union in Operation Barbarossa on 22 June 1941.^[74] That resulted in the Soviet Union becoming one of the main members of the Allies.

Germany then revived its Anti-Comintern Pact, enlisting many European and Asian countries in opposition to the Soviet Union. The Soviet Union and Japan remained neutral towards each other for most of the war by the Soviet-Japanese Neutrality Pact. The Soviet Union ended the Soviet-Japanese Neutrality Pact by invading Manchukuo on 9 August 1945, due to agreements reached at the Yalta Conference with Roosevelt and Churchill.

Caudillo Francisco Franco's Spanish State gave moral, economic, and military assistance to the Axis powers, while nominally maintaining neutrality. Franco described Spain as a member of the Axis and signed the Anti-Comintern Pact in 1941 with Hitler and Mussolini. Members of the ruling Falange party in Spain held irredentist designs on Gibraltar.^[185] Falangists also supported Spanish colonial acquisition of Tangier, French Morocco and northwestern French Algeria.^[186] In addition, Spain held ambitions on former Spanish colonies in Latin America.^[187] In June 1940 the Spanish government approached Germany to propose an alliance in exchange for Germany recognizing Spain's territorial aims: the annexation of the Oran province of Algeria, the incorporation of all Morocco, the extension of Spanish Sahara southward to the twentieth parallel, and the incorporation of French Cameroons into Spanish Guinea.^[188] Spain invaded and occupied the Tangier International Zone, maintaining its occupation until 1945.^[188] The occupation caused a dispute between Britain and Spain in November 1940; Spain conceded to protect British rights in the area and promised not to fortify the area.^[188] The Spanish government secretly held expansionist plans towards Portugal that it made known to the German government. In a communiqué with Germany on 26 May 1942, Franco declared that Portugal should be annexed into Spain.^[189]

Franco had previously won the Spanish Civil War with the help of Nazi Germany and Fascist Italy. Both were eager to establish another fascist state in Europe. Spain owed Germany over $212 million^[190] for supplies of matériel during the Spanish Civil War, and Italian combat troops had actually fought in Spain on the side of Franco's Nationalists.

From 1940 to 1941, Franco endorsed a Latin Bloc of Italy, Vichy France, Spain, and Portugal, with support from the Vatican in order to balance the countries' powers to that of Germany.^[106] Franco discussed the Latin Bloc alliance with Pétain of Vichy France in Montpellier, France in 1940, and with Mussolini in Bordighera, Italy.^[106]

When Germany invaded the Soviet Union in 1941, Franco immediately offered to form a unit of military volunteers to join the invasion. This was accepted by Hitler and, within two weeks, there were more than enough volunteers to form a division – the Blue Division (División Azul) under General Agustín Muñoz Grandes.

The possibility of Spanish intervention in World War II was of concern to the United States, which investigated the activities of Spain's ruling Falange party in Latin America, especially Puerto Rico, where pro-Falange and pro-Franco sentiment was high, even amongst the ruling upper classes.^[191] The Falangists promoted the idea of supporting Spain's former colonies in fighting against American domination.^[187] Prior to the outbreak of war, support for Franco and the Falange was high in the Philippines.^[192] The Falange Exterior, the international department of the Falange, collaborated with Japanese forces against U.S. and Filipino forces in the Philippines through the Philippine Falange.^[193]

Although officially neutral, Marshal Philippe Pétain's "Vichy regime" collaborated with the Axis from its creation on 10 July 1940. It retained full control of the non-occupied part of France until November 1942 – when the whole of France was occupied by Germany – and of a large part of France's colonial empire, until the colonies gradually fell under Free French control.

The German invasion army entered Paris on 14 June 1940, following the battle of France. Pétain became the last Prime Minister of the French Third Republic on 16 June 1940. He sued for peace with Germany and on 22 June 1940, the French government concluded an armistice with Hitler. Under the terms of the agreement, Germany occupied two-thirds of France, including Paris. Pétain was permitted to keep an "armistice army" of 100,000 men within the unoccupied southern zone. This number included neither the army based in the French colonial empire nor the French fleet. In Africa the Vichy regime was permitted to maintain 127,000.^[194] The French also maintained substantial garrisons at the French-mandated territory of Syria and Greater Lebanon, the French colony of Madagascar, and in French Somaliland. Some members of the Vichy government pushed for closer cooperation, but they were rebuffed by Pétain. Neither did Hitler accept that France could ever become a full military partner,^[195] and constantly prevented the buildup of Vichy's military strength.

After the armistice, relations between the Vichy French and the British quickly worsened. Although the French had told Churchill they would not allow their fleet to be taken by the Germans, the British launched several naval attacks, the most notable of which was against the Algerian harbour of Mers el-Kebir on 3 July 1940. Though Churchill defended his controversial decision to attack the French fleet, the action deteriorated greatly the relations between France and Britain. German propaganda trumpeted these attacks as an absolute betrayal of the French people by their former allies.

On 10 July 1940, Pétain was given emergency "full powers" by a majority vote of the French National Assembly. The following day approval of the new constitution by the Assembly effectively created the French State (l'État Français), replacing the French Republic with the government unofficially called "Vichy France," after the resort town of Vichy, where Pétain maintained his seat of government. This continued to be recognised as the lawful government of France by the neutral United States until 1942, while the United Kingdom had recognised de Gaulle's government-in-exile in London. Racial laws were introduced in France and its colonies and many foreign Jews in France were deported to Germany. Albert Lebrun, last President of the Republic, did not resign from the presidential office when he moved to Vizille on 10 July 1940. By 25 April 1945, during Pétain's trial, Lebrun argued that he thought he would be able to return to power after the fall of Germany, since he had not resigned.^[196]

In September 1940, Vichy France was forced to allow Japan to occupy French Indochina, a federation of French colonial possessions and protectorates encompassing modern day Vietnam, Laos, and Cambodia. The Vichy regime continued to administer them under Japanese military occupation. French Indochina was the base for the Japanese invasions of Thailand, Malaya, and the Dutch East Indies. In 1945, under Japanese sponsorship, the Empire of Vietnam and the Kingdom of Kampuchea were proclaimed as Japanese puppet states.

On 26 September 1940, de Gaulle led an attack by Allied forces on the Vichy port of Dakar in French West Africa. Forces loyal to Pétain fired on de Gaulle and repulsed the attack after two days of heavy fighting, drawing Vichy France closer to Germany.

During the Anglo–Iraqi War of May 1941, Vichy France allowed Germany and Italy to use air bases in the French mandate of Syria to support the Iraqi revolt. British and Free French forces attacked later Syria and Lebanon in June–July 1941, and in 1942 Allied forces took over French Madagascar. More and more colonies abandoned Vichy, joining the Free French territories of French Equatorial Africa, Polynesia, New Caledonia and others who had sided with de Gaulle from the start.

In November 1942 Vichy French troops briefly resisted the landing of Allied troops in French North Africa for a couple of days, until Admiral François Darlan negotiated a local ceasefire with the Allies. In response to the landings, Axis troops invaded the non-occupied zone in southern France and ended Vichy France as an entity with any kind of autonomy; it then became a puppet government for the occupied territories.

In June 1943, the formerly Vichy-loyal colonial authorities in French North Africa led by Henri Giraud came to an agreement with the Free French to merge with their own interim regime with the French National Committee (Comité Français National, CFN) to form a provisional government in Algiers, known as the French Committee of National Liberation (Comité Français de Libération Nationale, CFLN) initially led by Darlan. After his assassination De Gaulle emerged as the uncontested French leader. The CFLN raised more troops and re-organised, re-trained and re-equipped the Free French military, in cooperation with Allied forces in preparation of future operations against Italy and the German Atlantic wall.

In 1943 the Milice, a paramilitary force which had been founded by Vichy, was subordinated to the Germans and assisted them in rounding up opponents and Jews, as well as fighting the French Resistance. The Germans recruited volunteers in units independent of Vichy. Partly as a result of the great animosity of many right-wingers against the pre-war Front Populaire, volunteers joined the German forces in their anti-communist crusade against the USSR. Almost 7,000 joined Légion des Volontaires Français (LVF) from 1941 to 1944. The LVF then formed the cadre of the Waffen-SS Division Charlemagne in 1944–1945, with a maximum strength of some 7,500. Both the LVF and the Division Charlemagne fought on the eastern front.

Deprived of any military assets, territory or resources, the members of the Vichy government continued to fulfil their role as German puppets, being quasi-prisoners in the so-called "Sigmaringen enclave" in a castle in Baden-Württemberg at the end of the war in May 1945.

On 7 December 1941, Japan attacked the US naval bases in Pearl Harbor, Hawaii. According to the stipulation of the Tripartite Pact, Nazi Germany and Fascist Italy were required to come to the defense of their allies only if they were attacked. Since Japan had made the first move, Germany and Italy were not obliged to aid her until the United States counterattacked. Nevertheless, expecting the US to declare war on Germany in any event,^[197] Hitler ordered the Reichstag to formally declare war on the United States.^[198] Italy also declared war on the U.S..

Historian Ian Kershaw suggests that this declaration of war against the United States was a serious blunder made by Germany and Italy, as it allowed the United States to join the war in Europe and North Africa without any limitation.^[199] On the other hand, American destroyers escorting convoys had been effectively intervening in the Battle of the Atlantic with German and Italian ships and submarines, and the immediate war declaration made the Second Happy Time possible for U-boats.^[200] The US had effectively abandoned its strictly neutral stance in September 1940 with the Destroyers for Bases Agreement, before dropping all pretence of neutrality in March 1941 with the beginning of Lend-Lease. Following the "Greer incident" on 4 September 1941, when the German submarine U-652 fired on the American destroyer Greer, Roosevelt confirmed that all US ships escorting convoys had been ordered to "shoot on sight" at all Axis ships and submarines in the Atlantic.^[201] This order effectively declared naval war on Germany and Italy.^[202] In the "Kearny incident" on 17 October 1941 the USS Kearny (DD-432) dropped depth charges on German U-Boats, before being torpedoed by German submarine U-568 - 11 American servicemen were killed and 22 injured. The US destroyer Reuben James was torpedoed and sunk by the submarine U-552 on 31 October 1941. Roosevelt had said in his Fireside Chat on 9 December 1941 that Germany and Italy considered themselves to be in a state of war with the United States.^[203] Plans for Rainbow Five had been published by the press early in December 1941,^[204] and Hitler could no longer ignore the amount of economic and military aid the US was giving Britain and the USSR.^[205] The Plan Dog memo had determined in 1940 that the US would pursue a Europe first strategy by focusing on defeating Germany and Italy while fighting a defensive war in the Pacific.^[206] Americans played key roles in financing and supplying the Allies, in the strategic bombardment of Germany, and in the final invasion of the European continent.