The Vietnam War ( Vietnamese : Chiến tranh Việt Nam ), also known as the Second Indochina War ,  and known in Vietnam as Resistance War Against America ( Vietnamese : Kháng chiến chống Mỹ ) or simply the American War , was a Cold War -era proxy war  that occurred in Vietnam , Laos , and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War (1946–54) and was fought between North Vietnam —supported by the Soviet Union, China and other communist allies—and the government of South Vietnam —supported by the United States, Philippines and other anti-communist allies .  The Viet Cong (also known as the National Liberation Front, or NLF), a South Vietnamese communist common front aided by the North, fought a guerrilla war against anti-communist forces in the region. The People's Army of Vietnam , also known as the North Vietnamese Army (NVA), engaged in a more conventional war , at times committing large units to battle.
As the war continued, the part of the Viet Cong in the fighting decreased as the role of the NVA grew. U.S. and South Vietnamese forces relied on air superiority and overwhelming firepower to conduct search and destroy operations, involving ground forces , artillery , and airstrikes . In the course of the war, the U.S. conducted a large-scale strategic bombing campaign against North Vietnam.
The U.S. government viewed its involvement in the war as a way to prevent a Communist takeover of South Vietnam. This was part of a wider containment policy , with the stated aim of stopping the spread of communism. The North Vietnamese government and the Viet Cong were fighting to reunify Vietnam. They viewed the conflict as a colonial war , fought initially against forces from France and then the U.S., and later against South Vietnam. 
Beginning in 1950, American military advisors arrived in what was then French Indochina .  U.S. involvement escalated in the early 1960s, with troop levels tripling in 1961 and again in 1962.  U.S. involvement escalated further following the 1964 Gulf of Tonkin incident , in which a U.S. destroyer clashed with North Vietnamese fast attack craft, which was followed by the Gulf of Tonkin Resolution , which gave the U.S. president authorization to increase U.S. military presence. Regular U.S. combat units were deployed beginning in 1965. Operations crossed international borders: bordering areas of Laos and Cambodia were heavily bombed by U.S. forces as American involvement in the war peaked in 1968, the same year that the communist side launched the Tet Offensive . The Tet Offensive failed in its goal of overthrowing the South Vietnamese government, but became the turning point in the war, as it persuaded a large segment of the U.S. population that its government's claims of progress toward winning the war were illusory despite many years of massive U.S. military aid to South Vietnam.
Gradual withdrawal of U.S. ground forces began as part of " Vietnamization ", which aimed to end American involvement in the war while transferring the task of fighting the Communists to the South Vietnamese themselves. Despite the Paris Peace Accord , which was signed by all parties in January 1973, the fighting continued. In the U.S. and the Western world, a large anti-Vietnam War movement developed as part of a larger counterculture . The war changed the dynamics between the Eastern and Western Blocs , and altered North–South relations . 
Direct U.S. military involvement ended on 15 August 1973. The capture of Saigon by the North Vietnamese Army in April 1975 marked the end of the war, and North and South Vietnam were reunified the following year. The war exacted a huge human cost in terms of fatalities (see Vietnam War casualties ). Estimates of the number of Vietnamese soldiers and civilians killed vary from 800,000  to 3.1 million. Some 200,000–300,000 Cambodians , 20,000–200,000 Laotians ,     and 58,220 U.S. service members also died in the conflict, with a further 1,626 missing in action.
Names for the war
Various names have been applied to the conflict. Vietnam War is the most commonly used name in English. It has also been called the Second Indochina War and the Vietnam Conflict .
As there have been several conflicts in Indochina, this particular conflict is known by the names of its primary protagonists to distinguish it from others.  In Vietnamese , the war is generally known as Kháng chiến chống Mỹ (Resistance War Against America). It is also called Chiến tranh Việt Nam (The Vietnam War). 
The primary military organizations involved in the war were, on one side, the Army of the Republic of Vietnam (ARVN) and the U.S. military , and, on the other side, the People's Army of Vietnam (PAVN) (more commonly called the North Vietnamese Army, or NVA, in English-language sources), and the National Front for the Liberation of South Vietnam (NLF, more commonly known as the Viet Cong in English language sources), a South Vietnamese communist guerrilla force.
Background to 1949
France began its conquest of Indochina in the late 1850s, and completed pacification by 1893.    The 1884 Treaty of Huế formed the basis for French colonial rule in Vietnam for the next seven decades. In spite of military resistance, most notably by the Cần Vương of Phan Đình Phùng , by 1888 the area of the current-day nations of Cambodia and Vietnam was made into the colony of French Indochina (Laos was later added to the colony). Various Vietnamese opposition movements to French rule existed during this period, such as the Việt Nam Quốc Dân Đảng who staged the failed Yên Bái mutiny in 1930, but none were ultimately as successful as the Viet Minh common front , which was founded in 1941, controlled by the Indochinese Communist Party , and funded by the U.S. and the Chinese Nationalist Party in its fight against Imperial Japanese occupation.
In 1940, during World War II, the French were defeated by the Germans . The French State (commonly known as Vichy France) was established as a client state of Nazi Germany . The French colonial authorities, in French Indochina, sided with the Vichy regime. In September 1940, Japan invaded Indochina . Following the cessation of fighting and the beginning of the Imperial Japanese occupation, the French colonial authorities collaborated with the Japanese. The French continued to run affairs in Indochina, but ultimate power resided in the hands of the Imperial Japanese.
The Viet Minh was founded as a league for independence from France, but also opposed Japanese occupation in 1945 for the same reason. The U.S. and Chinese Nationalist Party supported them in the fight against the Imperial Japanese.  However, they did not have enough power to fight actual battles at first. Viet Minh leader Ho Chi Minh was suspected of being a communist and jailed for a year by the Chinese Nationalist Party. 
Double occupation by France and Japan continued until the German forces were expelled from France and the French Indochina colonial authorities started holding secret talks with the Free French . Fearing that they could no longer trust the French authorities, the Imperial Japanese military interned the French authorities and troops on 9 March 1945 and created the puppet Empire of Vietnam state, under Bảo Đại instead.
During 1944–1945, a deep famine struck northern Vietnam due to a combination of bad weather and French/Japanese exploitation (French Indochina had to supply grains to Japan).  Between 400,000 and 2 million  people died of starvation (out of a population of 10 million in the affected area). Exploiting the administrative gap that the internment of the French had created, the Viet Minh in March 1945 urged the population to ransack rice warehouses and refuse to pay their taxes. Between 75 and 100 warehouses were consequently raided. This rebellion against the effects of the famine and the authorities that were partially responsible for it bolstered the Viet Minh's popularity and they recruited many members during this period.
On 22 August 1945, following the Imperial Japanese surrender , OSS agents Archimedes Patti and Carleton B. Swift Jr. arrived in Hanoi on a mercy mission to liberate allied POWs and were accompanied by Jean Sainteny , a French government official.  The Japanese forces informally surrendered (the official surrender took place on 2 September 1945 in Tokyo Bay) but being the only force capable of maintaining law and order the Imperial Japanese military remained in power while keeping French colonial troops and Sainteny detained.
During August the Imperial Japanese forces remained inactive as the Viet Minh and other nationalist groups took over public buildings and weapons, which began the August Revolution . OSS officers met repeatedly with Ho Chi Minh and other Viet Minh officers during this period  and on 2 September 1945 Ho Chi Minh declared the independent Democratic Republic of Vietnam before a crowd of 500,000 in Hanoi . In an overture to the Americans, he began his speech by paraphrasing the United States Declaration of Independence : "All men are created equal. The Creator has given us certain inviolable Rights: the right to Life, the right to be Free, and the right to achieve Happiness."
The Viet Minh took power in Vietnam in the August Revolution . The Viet Minh, downplaying their Communist agenda and stressing nationalism enjoyed large popular support (Vietnamese independence being popular at the time),  although Arthur J. Dommen cautions against a "romanticized view" of their success: "The Viet Minh use of terror was systematic….the party had drawn up a list of those to be liquidated without delay."  After their defeat in the war, the Imperial Japanese Army (IJA) gave weapons to the Vietnamese, and kept Vichy French officials and military officers imprisoned for a month after the surrender. The Viet Minh had recruited more than 600 Imperial Japanese soldiers and given them roles to train or command Vietnamese soldiers.  
However, the major allied victors of World War II , the United Kingdom, the United States, and the Soviet Union, all agreed the area belonged to the French. As the French did not have the means to immediately retake Vietnam, the major powers came to an agreement that British troops would occupy the south while Nationalist Chinese forces would move in from the north. Nationalist Chinese troops entered the country to disarm Imperial Japanese troops north of the 16th parallel on 14 September 1945.  When the British landed in the south, they rearmed the interned French forces as well as parts of the surrendered Imperial Japanese forces to aid them in retaking southern Vietnam, as they did not have enough troops to do this themselves.
On the urging of the Soviet Union, Ho Chi Minh initially attempted to negotiate with the French, who were slowly re-establishing their control across the area. In January 1946, the Viet Minh won elections across central and northern Vietnam. On 6 March 1946, Ho signed an agreement allowing French forces to replace Nationalist Chinese forces, in exchange for French recognition of the Democratic Republic of Vietnam as a "free" republic within the French Union , with the specifics of such recognition to be determined by future negotiation.    The French landed in Hanoi by March 1946 and in November of that year they ousted the Viet Minh from the city. British forces departed on 26 March 1946, leaving Vietnam in the hands of the French.  Soon thereafter, the Viet Minh began a guerrilla war against the French Union forces, beginning the First Indochina War .
The war spread to Laos and Cambodia, where communists organized the Pathet Lao and the Khmer Serei , both of which were modeled on the Viet Minh. Globally, the Cold War began in earnest, which meant that the rapprochement that existed between the Western powers and the Soviet Union during World War II disintegrated. The Viet Minh fight was hampered by a lack of weapons; this situation changed by 1949 when the Chinese Communists had largely won the Chinese Civil War and were free to provide arms to their Vietnamese allies.
Exit of the French, 1950–54
In January 1950, the People's Republic of China and the Soviet Union recognized the Viet Minh's Democratic Republic of Vietnam , based in Hanoi , as the legitimate government of Vietnam. The following month the United States and Great Britain recognized the French-backed State of Vietnam in Saigon , led by former Emperor Bảo Đại , as the legitimate Vietnamese government.  The outbreak of the Korean War in June 1950 convinced many Washington policymakers that the war in Indochina was an example of communist expansionism directed by the Soviet Union. 
Military advisors from the People's Republic of China (PRC) began assisting the Viet Minh in July 1950. PRC weapons, expertise, and laborers transformed the Viet Minh from a guerrilla force into a regular army. In September 1950, the United States created a Military Assistance and Advisory Group (MAAG) to screen French requests for aid, advise on strategy, and train Vietnamese soldiers. By 1954, the United States had supplied 300,000 small arms and spent US$1 billion in support of the French military effort, shouldering 80 percent of the cost of the war. 
There were also talks between the French and Americans in which the possible use of three tactical nuclear weapons was considered, though reports of how seriously this was considered and by whom are even now vague and contradictory.  One version of the plan for the proposed Operation Vulture envisioned sending 60 B-29s from U.S. bases in the region, supported by as many as 150 fighters launched from U.S. Seventh Fleet carriers, to bomb Viet Minh commander Võ Nguyên Giáp 's positions. The plan included an option to use up to three atomic weapons on the Viet Minh positions. Admiral Arthur W. Radford , Chairman of the U.S. Joint Chiefs of Staff , gave this nuclear option his backing. U.S. B-29s, B-36s, and B-47s could have executed a nuclear strike, as could carrier aircraft from the Seventh Fleet. 
U.S. carriers sailed to the Gulf of Tonkin , and reconnaissance flights over Dien Bien Phu were conducted during the negotiations. According to U.S. Vice-President Richard Nixon , the plan involved the Joint Chiefs of Staff drawing up plans to use three small tactical nuclear weapons in support of the French. Nixon, a so-called " hawk " on Vietnam, suggested that the United States might have to "put American boys in".  U.S. President Dwight D. Eisenhower made American participation contingent on British support, but they were opposed to such a venture.  In the end, convinced that the political risks outweighed the possible benefits, Eisenhower decided against the intervention. Eisenhower was a five-star general . He was wary of getting the United States involved in a land war in Asia. 
The Viet Minh received crucial support from the Soviet Union and PRC. PRC support in the Border Campaign of 1950 allowed supplies to come from the PRC into Vietnam. Throughout the conflict, U.S. intelligence estimates remained skeptical of French chances of success. 
The Battle of Dien Bien Phu marked the end of French involvement in Indochina. Giap's Viet Minh forces handed the French a stunning military defeat, and on 7 May 1954, the French Union garrison surrendered. At the Geneva Conference , the French negotiated a ceasefire agreement with the Viet Minh, and independence was granted to Cambodia, Laos, and Vietnam.
Vietnam was temporarily partitioned at the 17th parallel , and under the terms of the Geneva Accords, civilians were to be given the opportunity to move freely between the two provisional states for a 300-day period. Elections throughout the country were to be held in 1956 to establish a unified government.  Around one million northerners, mainly minority Catholics, fled south, fearing persecution by the communists  following an American propaganda campaign using slogans such as "The Virgin Mary is heading south", and aided by a U.S.-funded $93 million relocation program, which included the use of the Seventh Fleet to ferry refugees. As many as two million more would have left had they not been stopped by the Viet Minh . The northern, mainly Catholic refugees were meant to give the later Ngô Đình Diệm regime a strong anti-communist constituency. Diệm later went on to staff his administration's key posts mostly with northern and central Catholics.
In addition to the Catholics flowing south, up to 130,000 "Revolutionary Regroupees" went to the north for "regroupment", expecting to return to the south within two years. The Viet Minh left roughly 5,000 to 10,000 cadres in the south as a "politico-military substructure within the object of its irredentism ." The last French soldiers were to leave Vietnam in April 1956. The PRC completed its withdrawal from North Vietnam at around the same time. Around 52,000 Vietnamese civilians moved from south to north. 
Between 1953 and 1956, the North Vietnamese government instituted various agrarian reforms, including "rent reduction" and "land reform", which resulted in significant political oppression. During the land reform, testimony from North Vietnamese witnesses suggested a ratio of one execution for every 160 village residents, which extrapolated nationwide would indicate nearly 100,000 executions. Because the campaign was concentrated mainly in the Red River Delta area, a lower estimate of 50,000 executions became widely accepted by scholars at the time.  However, declassified documents from the Vietnamese and Hungarian archives indicate that the number of executions was much lower than reported at the time, although likely greater than 13,500.  In 1956, leaders in Hanoi admitted to "excesses" in implementing this program and restored a large amount of the land to the original owners.
The south, meanwhile, constituted the State of Vietnam, with Bảo Đại as Emperor and Ngô Đình Diệm (appointed in July 1954) as his prime minister. Neither the United States government nor Ngô Đình Diệm's State of Vietnam signed anything at the 1954 Geneva Conference . With respect to the question of reunification, the non-communist Vietnamese delegation objected strenuously to any division of Vietnam, but lost out when the French accepted the proposal of Viet Minh delegate Phạm Văn Đồng , who proposed that Vietnam eventually be united by elections under the supervision of "local commissions". The United States countered with what became known as the "American Plan", with the support of South Vietnam and the United Kingdom. It provided for unification elections under the supervision of the United Nations, but was rejected by the Soviet delegation. The United States said, "With respect to the statement made by the representative of the State of Vietnam, the United States reiterates its traditional position that peoples are entitled to determine their own future and that it will not join in any arrangement which would hinder this".
U.S. President Dwight D. Eisenhower wrote in 1954, "I have never talked or corresponded with a person knowledgeable in Indochinese affairs who did not agree that had elections been held as of the time of the fighting, possibly eighty percent of the population would have voted for the Communist Ho Chi Minh as their leader rather than Chief of State Bảo Đại. Indeed, the lack of leadership and drive on the part of Bảo Đại was a factor in the feeling prevalent among Vietnamese that they had nothing to fight for." According to the Pentagon Papers , however, from 1954 to 1956 "Ngô Đình Diệm really did accomplish miracles" in South Vietnam: "It is almost certain that by 1956 the proportion which might have voted for Ho—in a free election against Diệm —would have been much smaller than eighty percent." In 1957, independent observers from India, Poland, and Canada representing the International Control Commission (ICC) stated that fair, unbiased elections were not possible, with the ICC reporting that neither South nor North Vietnam had honored the armistice agreement
From April to June 1955, Diệm eliminated any political opposition in the south by launching military operations against two religious groups: the Cao Đài and Hòa Hảo of Ba Cụt . The campaign also focused on the Bình Xuyên organized crime group which was allied with members of the communist party secret police and had some military elements. As broad-based opposition to his harsh tactics mounted, Diệm increasingly sought to blame the communists.
In a referendum on the future of the State of Vietnam on 23 October 1955, Diệm rigged the poll supervised by his brother Ngô Đình Nhu and was credited with 98.2 percent of the vote, including 133% in Saigon. His American advisors had recommended a more modest winning margin of "60 to 70 percent." Diệm, however, viewed the election as a test of authority. Three days later, he declared South Vietnam to be an independent state under the name Republic of Vietnam (ROV), with himself as president. Likewise, Ho Chi Minh and other communist officials always won at least 99% of the vote in North Vietnamese "elections". 
The domino theory , which argued that if one country fell to communism, then all of the surrounding countries would follow, was first proposed as policy by the Eisenhower administration. John F. Kennedy , then a U.S. Senator , said in a speech to the American Friends of Vietnam : "Burma, Thailand, India, Japan, the Philippines and obviously Laos and Cambodia are among those whose security would be threatened if the Red Tide of Communism overflowed into Vietnam." 
Diệm era, 1955–63
A devout Roman Catholic , Diệm was fervently anti-communist, nationalist, and socially conservative. Historian Luu Doan Huynh notes that "Diệm represented narrow and extremist nationalism coupled with autocracy and nepotism ." The majority of Vietnamese people were Buddhist , and were alarmed by actions such as Diệm's dedication of the country to the Virgin Mary .
Beginning in the summer of 1955, Diệm launched the "Denounce the Communists" campaign, during which communists and other anti-government elements were arrested, imprisoned, tortured, or executed. He instituted the death penalty against any activity deemed communist in August 1956.  According to Gabriel Kolko about 12,000 suspected opponents of Diệm were killed between 1955 and 1957 and by the end of 1958 an estimated 40,000 political prisoners had been jailed.  However, Guenter Lewy argues that such figures were exaggerated and that there were never more than 35,000 prisoners of all kinds in the whole country.
In May 1957, Diệm undertook a ten-day state visit to the United States . President Eisenhower pledged his continued support, and a parade was held in Diệm's honor in New York City. Although Diệm was publicly praised, in private Secretary of State John Foster Dulles conceded that Diệm had been selected because there were no better alternatives.
Former Secretary of Defense Robert McNamara wrote in Argument Without End (1999) that the new American patrons of the Republic of Vietnam (ROV) were almost completely ignorant of Vietnamese culture. They knew little of the language or long history of the country. There was a tendency to assign American motives to Vietnamese actions, though Diệm warned that it was an illusion to believe that blindly copying Western methods would solve Vietnamese problems.
Insurgency in the South, 1954–60
Between 1954 and 1957 there was large-scale but disorganized dissidence in the countryside which the Diệm government succeeded in quelling. In early 1957 South Vietnam had its first peace in over a decade. However, by mid-1957 through 1959 incidents of violence increased but the government "did not construe it as a campaign, considering the disorders too diffuse to warrant committing major GVN [Government of Vietnam] resources." By early 1959 however, Diệm considered it an organized campaign and implemented Law 10/59, which made political violence punishable by death and property confiscation.  There had been some division among former Viet Minh whose main goal was to hold the elections promised in the Geneva Accords, leading to " wildcat " activities separate from the other communists and anti-GVN activists. 
In December 1960, the National Liberation Front (NLF, a.k.a. the Viet Cong) was formally created with the intent of uniting all anti-GVN activists, including non-communists. According to the Pentagon Papers , the Viet Cong "placed heavy emphasis on the withdrawal of American advisors and influence, on land reform and liberalization of the GVN, on coalition government and the neutralization of Vietnam." Often the leaders of the organization were kept secret. 
The reason for the continued survival of the NLF was the class relations in the countryside. The vast majority of the population lived in villages in the countryside where the key issue was land reform. The Viet Minh had reduced rents and debts; and had leased communal lands, mostly to the poorer peasants. Diem brought the landlords back to the villages. People who were farming land they held for years now had to return it to landlords and pay years of back rent. This rent collection was enforced by the South Vietnamese army. The divisions within villages reproduced those that had existed against the French: "75 percent support for the NLF, 20 percent trying to remain neutral and 5 percent firmly pro-government," 
North Vietnamese involvement
Sources disagree on whether North Vietnam played a direct role in aiding and organizing South Vietnamese rebels prior to 1960. Kahin and Lewis assert:
Contrary to United States policy assumptions, all available evidence shows that the revival of the civil war in the South in 1958 was undertaken by Southerners at their own—not Hanoi's—initiative…Insurgency activity against the Saigon government began in the South under Southern leadership not as a consequence of any dictate from Hanoi, but contrary to Hanoi's injunctions. 
Similarly, historian Arthur Schlesinger Jr. states that "it was not until September, 1960 that the Communist Party of North Vietnam bestowed its formal blessing and called for the liberation of the south from American imperialism". 
By contrast, the author of War Comes to Long An Jeffrey Race interviewed communist defectors in 1967 and 1968 who found such denials "very amusing", and who "commented humorously that the Party had apparently been more successful than was expected in concealing its role."  James Olson and Randy Roberts assert that North Vietnam authorized a low-level insurgency in December 1956. To counter the accusation that North Vietnam was violating the Geneva Accord, the independence of the Viet Cong was stressed in communist propaganda. 
In March 1956, southern communist leader Lê Duẩn presented a plan to revive the insurgency entitled "The Road to the South" to the other members of the Politburo in Hanoi, but as both China and the Soviets opposed confrontation at this time, Lê Duẩn's plan was rejected.  However the North Vietnamese leadership approved tentative measures to revive the southern insurgency in December 1956. Communist forces were under a single command structure set up in 1958. The North Vietnamese Communist Party approved a "people's war" on the South at a session in January 1959 and in May, Group 559 was established to maintain and upgrade the Ho Chi Minh trail , at this time a six-month mountain trek through Laos. About 500 of the "regroupees" of 1954 were sent south on the trail during its first year of operation. The first arms delivery via the trail was completed in August 1959.
North Vietnam invaded Laos in 1959, and used 30,000 men to build invasion routes through Laos and Cambodia by 1961.  About 40,000 communist soldiers infiltrated into the south from 1961–63.  North Vietnam sent 10,000 troops of the North Vietnamese Army to attack the south in 1964, and this figure increased to 100,000 in 1965. 
Kennedy's escalation, 1961–63
In the 1960 U.S. presidential election , Senator John F. Kennedy defeated incumbent Vice President Richard Nixon . Although Eisenhower warned Kennedy about Laos and Vietnam, Europe and Latin America "loomed larger than Asia on his sights." In his inaugural address, Kennedy made the ambitious pledge to "pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and success of liberty."  In June 1961, he bitterly disagreed with Soviet premier Nikita Khrushchev when they met in Vienna to discuss key U.S.–Soviet issues. Only 16 months later, the U.S.–Soviet issues included the Cuban Missile Crisis (October 16–28, 1962) played out on television worldwide and was the closest the Cold War came to escalating into a full-scale nuclear war , and the U.S. raised the readiness level of Strategic Air Command (SAC) forces to DEFCON 2.
The Kennedy administration remained essentially committed to the Cold War foreign policy inherited from the Truman and Eisenhower administrations. In 1961, the U.S. had 50,000 troops based in Korea, and Kennedy faced a three-part crisis – the failure of the Bay of Pigs Invasion , the construction of the Berlin Wall , and a negotiated settlement between the pro-Western government of Laos and the Pathet Lao communist movement.  These crises made Kennedy believe that another failure on the part of the United States to gain control and stop communist expansion would fatally damage U.S. credibility with its allies and his own reputation. Kennedy was thus determined to "draw a line in the sand" and prevent a communist victory in Vietnam. He told James Reston of The New York Times immediately after his Vienna meeting with Khrushchev, "Now we have a problem making our power credible and Vietnam looks like the place."  
In May 1961, U.S. Vice President Lyndon B. Johnson visited Saigon and enthusiastically declared Diệm the " Winston Churchill of Asia." Asked why he had made the comment, Johnson replied, "Diệm's the only boy we got out there." Johnson assured Diệm of more aid in molding a fighting force that could resist the communists.
Kennedy's policy toward South Vietnam rested on the assumption that Diệm and his forces had to ultimately defeat the guerrillas on their own. He was against the deployment of American combat troops and observed that "to introduce U.S. forces in large numbers there today, while it might have an initially favorable military impact, would almost certainly lead to adverse political and, in the long run, adverse military consequences."  The quality of the South Vietnamese military, however, remained poor. Poor leadership, corruption, and political promotions all played a part in weakening the South Vietnamese Army (ARVN). The frequency of guerrilla attacks rose as the insurgency gathered steam. While Hanoi's support for the Viet Cong played a role, South Vietnamese governmental incompetence was at the core of the crisis.
One major issue Kennedy raised was whether the Soviet space and missile programs had surpassed those of the United States. Although Kennedy stressed long-range missile parity with the Soviets, he was also interested in using special forces for counterinsurgency warfare in Third World countries threatened by communist insurgencies. Although they were originally intended for use behind front lines after a conventional Soviet invasion of Europe, Kennedy believed that the guerrilla tactics employed by special forces such as the Green Berets would be effective in a "brush fire" war in Vietnam.
Kennedy advisors Maxwell Taylor and Walt Rostow recommended that U.S. troops be sent to South Vietnam disguised as flood relief workers. Kennedy rejected the idea but increased military assistance yet again. In April 1962, John Kenneth Galbraith warned Kennedy of the "danger we shall replace the French as a colonial force in the area and bleed as the French did."  By November 1963, there were 16,000 American military personnel in South Vietnam, up from Eisenhower's 900 advisors. 
The Strategic Hamlet Program was initiated in late 1961. This joint U.S.-South Vietnamese program attempted to resettle the rural population into fortified camps. It was implemented in early 1962 and involved some forced relocation, village internment, and segregation of rural South Vietnamese into new communities where the peasantry would be isolated from Communist insurgents. It was hoped these new communities would provide security for the peasants and strengthen the tie between them and the central government. However, by November 1963 the program had waned, and it officially ended in 1964.
On 23 July 1962, fourteen nations, including China, South Vietnam, the Soviet Union, North Vietnam and the United States, signed an agreement promising to respect the neutrality of Laos. 
Ousting and assassination of Ngô Đình Diệm
The inept performance of the South Vietnamese army was exemplified by failed actions such as the Battle of Ap Bac on 2 January 1963, in which a small band of Viet Cong won a battle against a much larger and better-equipped South Vietnamese force, many of whose officers seemed reluctant even to engage in combat.
The Army of the Republic of Vietnam forces were led in that battle by Diệm's most trusted general, Huỳnh Văn Cao , commander of the IV Corps . Cao was a Catholic who had been promoted due to religion and fidelity rather than skill, and his main job was to preserve his forces to stave off coups; he had earlier vomited during a communist attack. Some policymakers in Washington began to conclude that Diệm was incapable of defeating the communists and might even make a deal with Ho Chi Minh. He seemed concerned only with fending off coups, and had become more paranoid after attempts in 1960 and 1962, which he partly attributed to U.S. encouragement. As Robert F. Kennedy noted, "Diệm wouldn't make even the slightest concessions. He was difficult to reason with…"
As historian James Gibson summed up the situation:
Strategic hamlets had failed…. The South Vietnamese regime was incapable of winning the peasantry because of its class base among landlords. Indeed, there was no longer a 'regime' in the sense of a relatively stable political alliance and functioning bureaucracy. Instead, civil government and military operations had virtually ceased. The National Liberation Front had made great progress and was close to declaring provisional revolutionary governments in large areas.
Discontent with Diệm's policies exploded following the Huế Phật Đản shootings of nine majority Buddhists who were protesting against the ban on the Buddhist flag on Vesak , the Buddha's birthday. This resulted in mass protests against discriminatory policies that gave privileges to the Catholic Church and its adherents. Diệm's elder brother Ngô Đình Thục was the Archbishop of Huế and aggressively blurred the separation between church and state. Thuc's anniversary celebrations shortly before Vesak had been bankrolled by the government, and Vatican flags were displayed prominently. There had also been reports of Buddhist pagodas being demolished by Catholic paramilitaries throughout Diệm's rule. Diệm refused to make concessions to the Buddhist majority or take responsibility for the deaths. On 21 August 1963, the ARVN Special Forces of Colonel Lê Quang Tung , loyal to Diệm's younger brother Ngô Đình Nhu , raided pagodas across Vietnam , causing widespread damage and destruction and leaving a death toll estimated to range into the hundreds.
U.S. officials began discussing the possibility of a regime change during the middle of 1963. The United States Department of State was generally in favor of encouraging a coup, while the Defense Department favored Diệm. Chief among the proposed changes was the removal of Diệm's younger brother Nhu, who controlled the secret police and special forces and was seen as the man behind the Buddhist repression and more generally the architect of the Ngô family's rule. This proposal was conveyed to the U.S. embassy in Saigon in Cable 243 .
The Central Intelligence Agency (CIA) was in contact with generals planning to remove Diệm. They were told that the United States would not oppose such a move nor punish the generals by cutting off aid. President Diệm was overthrown and executed, along with his brother, on 2 November 1963. When he was informed, Maxwell Taylor remembered that Kennedy "rushed from the room with a look of shock and dismay on his face." He had not anticipated Diệm's murder. The U.S. ambassador to South Vietnam, Henry Cabot Lodge , invited the coup leaders to the embassy and congratulated them. Ambassador Lodge informed Kennedy that "the prospects now are for a shorter war". Kennedy wrote Lodge a letter congratulating him for "a fine job." 
Following the coup, chaos ensued. Hanoi took advantage of the situation and increased its support for the guerrillas. South Vietnam entered a period of extreme political instability, as one military government toppled another in quick succession. Increasingly, each new regime was viewed by the communists as a puppet of the Americans; whatever the failings of Diệm, his credentials as a nationalist (as Robert McNamara later reflected) had been impeccable.
U.S military advisors were embedded at every level of the South Vietnamese armed forces. They were however criticized for ignoring the political nature of the insurgency. The Kennedy administration sought to refocus U.S. efforts on pacification and "winning over the hearts and minds" of the population. The military leadership in Washington, however, was hostile to any role for U.S. advisors other than conventional troop training. General Paul Harkins , the commander of U.S. forces in South Vietnam, confidently predicted victory by Christmas 1963. The CIA was less optimistic, however, warning that "the Viet Cong by and large retain de facto control of much of the countryside and have steadily increased the overall intensity of the effort". 
Paramilitary officers from the CIA's Special Activities Division trained and led Hmong tribesmen in Laos and into Vietnam. The indigenous forces numbered in the tens of thousands and they conducted direct action missions, led by paramilitary officers, against the Communist Pathet Lao forces and their North Vietnamese supporters. The CIA also ran the Phoenix Program and participated in Military Assistance Command, Vietnam – Studies and Observations Group (MAC-V SOG), which was originally named the Special Operations Group, but was changed for cover purposes.
Johnson's escalation, 1963–69
At the time Lyndon B. Johnson took over the presidency after the death of Kennedy , he had not been heavily involved with policy toward Vietnam, Presidential aide Jack Valenti recalls, "Vietnam at the time was no bigger than a man's fist on the horizon. We hardly discussed it because it was not worth discussing."
Upon becoming president, however, Johnson immediately had to focus on Vietnam: on 24 November 1963, he said, "the battle against communism [...] must be joined [...] with strength and determination." The pledge came at a time when the situation in South Vietnam was deteriorating, especially in places like the Mekong Delta, because of the recent coup against Diệm.
The military revolutionary council, meeting in lieu of a strong South Vietnamese leader, was made up of 12 members headed by General Dương Văn Minh —whom Stanley Karnow , a journalist on the ground, later recalled as "a model of lethargy." Lodge, frustrated by the end of the year, cabled home about Minh: "Will he be strong enough to get on top of things?" His regime was overthrown in January 1964 by General Nguyễn Khánh . However, there was persistent instability in the military as several coups—not all successful—occurred in a short period of time.
On 2 August 1964, the USS Maddox , on an intelligence mission along North Vietnam's coast, allegedly fired upon and damaged several torpedo boats that had been stalking it in the Gulf of Tonkin . A second attack was reported two days later on the USS Turner Joy and Maddox in the same area. The circumstances of the attack were murky. Lyndon Johnson commented to Undersecretary of State George Ball that "those sailors out there may have been shooting at flying fish."
The second attack led to retaliatory air strikes , prompted Congress to approve the Gulf of Tonkin Resolution on 7 August 1964, signed by Johnson, and gave the president power to conduct military operations in Southeast Asia without declaring war. Although Congressmen at the time denied that this was a full-scale war declaration, the Tonkin Resolution allowed the president unilateral power to launch a full-scale war if the president deemed it necessary. In the same month, Johnson pledged that he was not "… committing American boys to fighting a war that I think ought to be fought by the boys of Asia to help protect their own land."
An undated NSA publication declassified in 2005, however, revealed that there was no attack on 4 August.  It had already been called into question long before this. " Gulf of Tonkin incident ", writes Louise Gerdes, "is an oft-cited example of the way in which Johnson misled the American people to gain support for his foreign policy in Vietnam." George C. Herring argues, however, that McNamara and the Pentagon "did not knowingly lie about the alleged attacks, but they were obviously in a mood to retaliate and they seem to have selected from the evidence available to them those parts that confirmed what they wanted to believe."
"From a strength of approximately 5,000 at the start of 1959 the Viet Cong's ranks grew to about 100,000 at the end of 1964…Between 1961 and 1964 the Army's strength rose from about 850,000 to nearly a million men." The numbers for U.S. troops deployed to Vietnam during the same period were quite different; 2,000 in 1961, rising rapidly to 16,500 in 1964. By early 1965, 7,559 South Vietnamese hamlets had been destroyed by the Viet Cong.
The National Security Council recommended a three-stage escalation of the bombing of North Vietnam. On 2 March 1965, following an attack on a U.S. Marine barracks at Pleiku ,  Operation Flaming Dart (initiated when Soviet Premier Alexei Kosygin was on a state visit to North Vietnam ), Operation Rolling Thunder and Operation Arc Light commenced. The bombing campaign, which ultimately lasted three years, was intended to force North Vietnam to cease its support for the Viet Cong by threatening to destroy North Vietnam's air defenses and industrial infrastructure. As well, it was aimed at bolstering the morale of the South Vietnamese. Between March 1965 and November 1968, "Rolling Thunder" deluged the north with a million tons of missiles, rockets and bombs.
Bombing was not restricted to North Vietnam. Other aerial campaigns, such as Operation Commando Hunt , targeted different parts of the Viet Cong and NVA infrastructure. These included the Ho Chi Minh trail supply route, which ran through Laos and Cambodia. The objective of stopping North Vietnam and the Viet Cong was never reached. As one officer noted, "This is a political war and it calls for discriminate killing. The best weapon… would be a knife… The worst is an airplane." The Chief of Staff of the United States Air Force Curtis LeMay , however, had long advocated saturation bombing in Vietnam and wrote of the communists that "we're going to bomb them back into the Stone Age". 
Escalation and ground war
After several attacks upon them, it was decided that U.S. Air Force bases needed more protection as the South Vietnamese military seemed incapable of providing security. On 8 March 1965, 3,500 U.S. Marines were dispatched to South Vietnam. This marked the beginning of the American ground war. U.S. public opinion overwhelmingly supported the deployment. 
In a statement similar to that made to the French almost two decades earlier, Ho Chi Minh warned that if the Americans "want to make war for twenty years then we shall make war for twenty years. If they want to make peace, we shall make peace and invite them to afternoon tea." As former First Deputy Foreign Minister Tran Quang Co has noted, the primary goal of the war was to reunify Vietnam and secure its independence. Some have argued that the policy of North Vietnam was not to topple other non-communist governments in South East Asia. However, the Pentagon Papers warned of "a dangerous period of Vietnamese expansionism….Laos and Cambodia would have been easy pickings for such a Vietnam….Thailand, Malaya, Singapore, and even Indonesia, could have been next."
The Marines' initial assignment was defensive. The first deployment of 3,500 in March 1965 was increased to nearly 200,000 by December. The U.S. military had long been schooled in offensive warfare. Regardless of political policies, U.S. commanders were institutionally and psychologically unsuited to a defensive mission. In December 1964, ARVN forces had suffered heavy losses at the Battle of Bình Giã ,  in a battle that both sides viewed as a watershed. Previously, communist forces had utilized hit-and-run guerrilla tactics. However, at Binh Gia, they had defeated a strong ARVN force in a conventional battle. Tellingly, South Vietnamese forces were again defeated in June 1965 at the Battle of Đồng Xoài .
Desertion rates were increasing, and morale plummeted. General William Westmoreland informed Admiral U. S. Grant Sharp Jr. , commander of U.S. Pacific forces, that the situation was critical. He said, "I am convinced that U.S. troops with their energy, mobility, and firepower can successfully take the fight to the NLF [National Front for the Liberation of South Vietnam a.k.a. the Viet Cong]." With this recommendation, Westmoreland was advocating an aggressive departure from America's defensive posture and the sidelining of the South Vietnamese. By ignoring ARVN units, the U.S. commitment became open-ended. Westmoreland outlined a three-point plan to win the war:
- Phase 1. Commitment of U.S. (and other free world) forces necessary to halt the losing trend by the end of 1965.
- Phase 2. U.S. and allied forces mount major offensive actions to seize the initiative to destroy guerrilla and organized enemy forces. This phase would end when the enemy had been worn down, thrown on the defensive, and driven back from major populated areas.
- Phase 3. If the enemy persisted, a period of twelve to eighteen months following Phase 2 would be required for the final destruction of enemy forces remaining in remote base areas.
The plan was approved by Johnson and marked a profound departure from the previous administration's insistence that the government of South Vietnam was responsible for defeating the guerrillas. Westmoreland predicted victory by the end of 1967. Johnson did not, however, communicate this change in strategy to the media. Instead he emphasized continuity. The change in U.S. policy depended on matching the North Vietnamese and the Viet Cong in a contest of attrition and morale . The opponents were locked in a cycle of escalation . The idea that the government of South Vietnam could manage its own affairs was shelved.
The one-year tour of duty of American soldiers deprived units of experienced leadership. As one observer noted "we were not in Vietnam for 10 years, but for one year 10 times." As a result, training programs were shortened.
South Vietnam was inundated with manufactured goods. As Stanley Karnow writes, "the main PX [Post Exchange], located in the Saigon suburb of Cholon , was only slightly smaller than the New York Bloomingdale's …" The American buildup transformed the economy and had a profound effect on South Vietnamese society. A huge surge in corruption was witnessed.
Washington encouraged its SEATO allies to contribute troops. Australia, New Zealand, South Korea, Thailand, and the Philippines all agreed to send troops. Major allies, however, notably NATO nations Canada and the United Kingdom, declined Washington's troop requests. The U.S. and its allies mounted complex operations, such as operations Masher , Attleboro , Cedar Falls , and Junction City . However, the communist insurgents remained elusive and demonstrated great tactical flexibility.
Meanwhile, the political situation in South Vietnam began to stabilize with the coming to power of prime minister Air Marshal Nguyễn Cao Kỳ and figurehead Chief of State, General Nguyễn Văn Thiệu , in mid-1965 at the head of a military junta. This ended a series of coups that had happened more than once a year. In 1967, Thieu became president with Ky as his deputy, after rigged elections. Although they were nominally a civilian government, Ky was supposed to maintain real power through a behind-the-scenes military body. However, Thieu outmaneuvered and sidelined Ky by filling the ranks with generals from his faction. Thieu was also accused of murdering Ky loyalists through contrived military accidents. Thieu, mistrustful and indecisive, remained president until 1975, having won a one-candidate election in 1971.
The Johnson administration employed a "policy of minimum candor" in its dealings with the media. Military information officers sought to manage media coverage by emphasizing stories that portrayed progress in the war. Over time, this policy damaged the public trust in official pronouncements. As the media's coverage of the war and that of the Pentagon diverged, a so-called credibility gap developed.
In late 1967 the Communists lured American forces into the hinterlands at Đắk Tô and at the Marine Khe Sanh combat base in Quảng Trị Province where the United States was more than willing to fight because it could unleash its massive firepower unimpeded by civilians. However, on 31 January 1968, the NVA and the Viet Cong broke the truce that traditionally accompanied the Tết (Lunar New Year) holiday by launching the largest battle of the war, the Tet Offensive, in the hope of sparking a national uprising. Over 100 cities were attacked by over 85,000 enemy troops including assaults on General Westmoreland's headquarters and the U.S. Embassy in Saigon .
Although the U.S. and South Vietnamese forces were initially shocked by the scale of the urban offensive, they responded quickly and effectively, decimating the ranks of the Viet Cong. In the former capital city of Huế , the combined NVA and Viet Cong troops captured the Imperial Citadel and much of the city and massacred over 3,000 unarmed Huế civilians. In the following Battle of Huế American forces employed massive firepower that left 80 percent of the city in ruins. Further north, at Quảng Trị City, members of the 1st Cavalry Division and 1st ARVN Infantry Division killed more than 900 NVA and Vietcong troops in and around the city. In Saigon, 1,000 NLF (Viet Cong) fighters fought off 11,000 U.S. and ARVN troops for three weeks.
Across South Vietnam, 1,100 Americans and other allied troops, 2,100 ARVN, 14,000 civilians, and 32,000 NVA and Viet Cong lay dead.
But the Tet Offensive had another, unintended consequence. General Westmoreland had become the public face of the war. He had been named Time magazine's 1965's Man of the Year and eventually was featured on the magazine's cover three times. Time described him as "the sinewy personification of the American fighting man… (who) directed the historic buildup, drew up the battle plans, and infused the… men under him with his own idealistic view of U.S. aims and responsibilities." Six weeks after the Tet Offensive began, "public approval of his overall performance dropped from 48 percent to 36 percent–and, more dramatically, endorsement for his handling of the war fell from 40 percent to 26 percent."
A few months earlier, in November 1967, Westmoreland had spearheaded a public relations drive for the Johnson administration to bolster flagging public support. In a speech before the National Press Club he had said a point in the war had been reached "where the end comes into view." Thus, the public was shocked and confused when Westmoreland's predictions were trumped by Tet. The American media, which had until then been largely supportive of U.S. efforts, turned on the Johnson administration for what had become an increasing credibility gap.
Although the Tet Offensive was a significant victory for allied forces, in terms of casualties and control of territory, it was a sound defeat when evaluated from the point of view of strategic consequences: it became a turning point in America's involvement in the Vietnam War because it had a profound impact on domestic support for the conflict. Despite the military failure for the Communist forces, the Tet Offensive became a political victory for them and ended the career of president Lyndon B. Johnson, who declined to run for re-election as his approval rating slumped from 48 to 36 percent. As James Witz noted, Tet "contradicted the claims of progress… made by the Johnson administration and the military." The offensive constituted an intelligence failure on the scale of Pearl Harbor . Journalist Peter Arnett , in a disputed article, quoted an officer he refused to identify, saying of Bến Tre (laid to rubble by U.S. attacks)  that "it became necessary to destroy the village in order to save it". 
Walter Cronkite said in an editorial, "To say that we are closer to victory today is to believe, in the face of the evidence, the optimists who have been wrong in the past. To suggest we are on the edge of defeat is to yield to unreasonable pessimism. To say that we are mired in stalemate seems the only realistic, yet unsatisfactory, conclusion."  Following Cronkite's editorial report, President Lyndon Johnson is reported to have said, "If I've lost Cronkite, I've lost Middle America ."  
Westmoreland became Chief of Staff of the Army in March 1968, just as all resistance was finally subdued. The move was technically a promotion. However, his position had become untenable because of the offensive and because his request for 200,000 additional troops had been leaked to the media. Westmoreland was succeeded by his deputy Creighton Abrams , a commander less inclined to public media pronouncements.
On 10 May 1968, despite low expectations, peace talks began between the United States and North Vietnam in Paris. Negotiations stagnated for five months, until Johnson gave orders to halt the bombing of North Vietnam.
As historian Robert Dallek writes, "Lyndon Johnson's escalation of the war in Vietnam divided Americans into warring camps… cost 30,000 American lives by the time he left office, (and) destroyed Johnson's presidency…" His refusal to send more U.S. troops to Vietnam was seen as Johnson's admission that the war was lost. It can be seen that the refusal was a tacit admission that the war could not be won by escalation, at least not at a cost acceptable to the American people. As Secretary of Defense Robert McNamara noted, "the dangerous illusion of victory by the United States was therefore dead."
Nixon Doctrine / Vietnamization
U.S. President Richard Nixon began troop withdrawals in 1969. His plan, called the Nixon Doctrine , was to build up the ARVN, so that they could take over the defense of South Vietnam. The policy became known as " Vietnamization ".
Nixon said in 1970 in an announcement, "I am tonight announcing plans for the withdrawal of an additional 150,000 American troops to be completed during the spring of next year. This will bring a total reduction of 265,500 men in our armed forces in Vietnam below the level that existed when we took office 15 months ago." 
On 10 October 1969, Nixon ordered a squadron of 18 B-52s loaded with nuclear weapons to race to the border of Soviet airspace to convince the Soviet Union, in accord with the madman theory , that he was capable of anything to end the Vietnam War.
Nixon also pursued negotiations. Theater commander Creighton Abrams shifted to smaller operations, aimed at communist logistics, with better use of firepower and more cooperation with the ARVN. Nixon also began to pursue détente with the Soviet Union and rapprochement with China . This policy helped to decrease global tensions. Détente led to nuclear arms reduction on the part of both superpowers. But Nixon was disappointed that China and the Soviet Union continued to supply the North Vietnamese with aid. In September 1969, Ho Chi Minh died at age seventy-nine.
The anti-war movement was gaining strength in the United States. Nixon appealed to the " silent majority " of Americans who he said supported the war without showing it in public. But revelations of the My Lai Massacre , in which a U.S. Army platoon raped and killed civilians, and the 1969 " Green Beret Affair " where eight Special Forces soldiers, including the 5th Special Forces Group Commander, were arrested for the murder of a suspected double agent  provoked national and international outrage.
Beginning in 1970, American troops were withdrawn from border areas where most of the fighting took place, and instead redeployed along the coast and interior, which is one reason why casualties in 1970 were less than half of 1969's totals. 
Cambodia and Laos
Prince Norodom Sihanouk had proclaimed Cambodia neutral since 1955, but the communists used Cambodian soil as a base and Sihanouk tolerated their presence, because he wished to avoid being drawn into a wider regional conflict. Under pressure from Washington, however, he changed this policy in 1969. The Vietnamese communists were no longer welcome. President Nixon took the opportunity to launch a massive bombing campaign, called Operation Menu, against communist sanctuaries along the Cambodia/Vietnam border. Only five high-ranking Congressional officials were informed of Operation Menu.
In 1970, Prince Sihanouk was deposed by his pro-American prime minister Lon Nol . North Vietnam invaded Cambodia in 1970 at the request of Khmer Rouge deputy leader Nuon Chea . U.S. and ARVN forces launched an invasion into Cambodia to attack NVA and Viet Cong bases.
This invasion sparked nationwide U.S. protests as Nixon had promised to deescalate the American involvement. Four students were killed by National Guardsmen at Kent State University during a protest in Ohio , which provoked further public outrage in the United States. The reaction to the incident by the Nixon administration was seen as callous and indifferent, providing additional impetus for the anti-war movement. The U.S. Air Force continued to heavily bomb Cambodia in support of the Cambodian government as part of Operation Freedom Deal .
In 1971 the Pentagon Papers were leaked to The New York Times . The top-secret history of U.S. involvement in Vietnam, commissioned by the Department of Defense, detailed a long series of public deceptions on the part of the U.S. government. The Supreme Court ruled that its publication was legal. 
The ARVN launched Operation Lam Son 719 in February 1971, aimed at cutting the Ho Chi Minh trail in Laos.  The ostensibly neutral Laos had long been the scene of a civil war, pitting the Laotian government backed by the US against the Pathet Lao and its North Vietnamese allies. After meeting resistance, ARVN forces retreated in a confused rout. They fled along roads littered with their own dead. When they exhausted fuel supplies, soldiers abandoned their vehicles and attempted to barge their way on to American helicopters sent to evacuate the wounded. Many ARVN soldiers clung to helicopter skids in a desperate attempt to save themselves. U.S. aircraft had to destroy abandoned equipment, including tanks, to prevent them from falling into enemy hands. Half of the ARVN troops involved in the operation were either captured or killed. The operation was a fiasco and represented a clear failure of Vietnamization. As Karnow noted "the blunders were monumental… The (South Vietnamese) government's top officers had been tutored by the Americans for ten or fifteen years, many at training schools in the United States, yet they had learned little."
In 1971 Australia and New Zealand withdrew their soldiers. The U.S. troop count was further reduced to 196,700, with a deadline to remove another 45,000 troops by February 1972. As peace protests spread across the United States, disillusionment and ill-discipline grew in the ranks  including increased drug use, " fragging " (the act of murdering the commander of a fighting unit) and desertions. 
Vietnamization was again tested by the Easter Offensive of 1972, a massive conventional NVA invasion of South Vietnam. The NVA and Viet Cong quickly overran the northern provinces and in coordination with other forces attacked from Cambodia, threatening to cut the country in half. U.S. troop withdrawals continued. But American airpower came to the rescue with Operation Linebacker , and the offensive was halted. However, it became clear that without American airpower South Vietnam could not survive. The last remaining American ground troops were withdrawn by the end of March 1973; U.S. naval and air forces remained in the Gulf of Tonkin, as well as Thailand and Guam.
1972 election and Paris Peace Accords
The war was the central issue of the 1972 U.S. presidential election . Nixon's opponent, George McGovern , campaigned on a platform of withdrawal from Vietnam. Nixon's National Security Advisor, Henry Kissinger , continued secret negotiations with North Vietnam's Lê Đức Thọ . In October 1972, they reached an agreement.
However, South Vietnamese president Thieu demanded massive changes to the peace accord. When North Vietnam went public with the agreement's details, the Nixon administration claimed that the North was attempting to embarrass the president. The negotiations became deadlocked. Hanoi demanded new changes.
To show his support for South Vietnam and force Hanoi back to the negotiating table, Nixon ordered Operation Linebacker II , a massive bombing of Hanoi and Haiphong 18–29 December 1972. The offensive destroyed much of the remaining economic and industrial capacity of North Vietnam. Simultaneously Nixon pressured Thieu to accept the terms of the agreement, threatening to conclude a bilateral peace deal and cut off American aid.
On 15 January 1973, Nixon announced the suspension of offensive action against North Vietnam. The Paris Peace Accords on "Ending the War and Restoring Peace in Vietnam" were signed on 27 January 1973, officially ending direct U.S. involvement in the Vietnam War. A cease-fire was declared across North and South Vietnam. U.S. prisoners of war were released. The agreement guaranteed the territorial integrity of Vietnam and, like the Geneva Conference of 1954, called for national elections in the North and South. The Paris Peace Accords stipulated a sixty-day period for the total withdrawal of U.S. forces. "This article", noted Peter Church, "proved… to be the only one of the Paris Agreements which was fully carried out."
Opposition to U.S. involvement in the Vietnam War: 1962–1973
During the course of the Vietnam War a large segment of the American population came to be opposed to U.S. involvement in South Vietnam. Public opinion steadily turned against the war following 1967 and by 1970 only a third of Americans believed that the U.S. had not made a mistake by sending troops to fight in Vietnam.
Nearly a third of the American population were strongly against the war. It is possible to specify certain groups who led the anti-war movement and the reasons why. Many young people protested because they were the ones being drafted while others were against the war because the anti-war movement grew increasingly popular among the counterculture and drug culture in American society and its music.
Some advocates within the peace movement advocated a unilateral withdrawal of U.S. forces from Vietnam. One reason given for the withdrawal is that it would contribute to a lessening of tensions in the region and thus less human bloodshed. Early opposition to U.S. involvement in Vietnam drew its inspiration from the Geneva Conference of 1954 . American support of Diệm in refusing elections was seen as thwarting the very democracy that America claimed to be supporting. John F. Kennedy, while Senator, opposed involvement in Vietnam.
Opposition to the Vietnam War tended to unite groups opposed to U.S. anti-communism and imperialism and, for those involved with the New Left such as the Catholic Worker Movement . Others, such as Stephen Spiro opposed the war based on the theory of Just War . Some wanted to show solidarity with the people of Vietnam, such as Norman Morrison emulating the actions of Thích Quảng Đức . In a key televised debate from 15 May 1965, Eric Severeid reporting for CBS conducted a debate between McGeorge Bundy and Hans Morgenthau dealing with an acute summary of the main war concerns of the U.S. as seen at that time stating them as: "(1) What are the justifications for the American presence in Vietnam – why are we there? (2) What is the fundamental nature of this war? Is it aggression from North Vietnam or is it basically, a civil war between the peoples of South Vietnam? (3) What are the implications of this Vietnam struggle in terms of Communist China's power and aims and future actions? And (4) What are the alternatives to our present policy in Vietnam?"
High-profile opposition to the Vietnam War turned to street protests in an effort to turn U.S. political opinion. On 15 October 1969, the Vietnam Moratorium attracted millions of Americans.  Riots broke out at the 1968 Democratic National Convention during protests against the war. After news reports of American military abuses such as the 1968 My Lai Massacre , brought new attention and support to the anti-war movement, some veterans joined Vietnam Veterans Against the War . The fatal shooting of four students at Kent State University in 1970 led to nationwide university protests.  Anti-war protests ended with the final withdrawal of troops after the Paris Peace Accords were signed in 1973. South Vietnam was left to defend itself alone when the fighting resumed. Many South Vietnamese subsequently fled to the United States. 
Exit of the Americans: 1973–75
The United States began drastically reducing their troop support in South Vietnam during the final years of Vietnamization . Many U.S. troops were removed from the region, and on 5 March 1971, the United States returned the 5th Special Forces Group , which was the first American unit deployed to South Vietnam , to its former base in Fort Bragg , North Carolina .
Under the Paris Peace Accords , between North Vietnamese Foreign Minister Lê Đức Thọ and U.S. Secretary of State Henry Kissinger, and reluctantly signed by South Vietnamese president Thiệu , U.S. military forces withdrew from South Vietnam and prisoners were exchanged. North Vietnam was allowed to continue supplying communist troops in the South, but only to the extent of replacing expended materiel. Later that year the Nobel Peace Prize was awarded to Kissinger and Thọ, but the Vietnamese negotiator declined it saying that a true peace did not yet exist.
The communist leaders had expected that the ceasefire terms would favor their side. But Saigon, bolstered by a surge of U.S. aid received just before the ceasefire went into effect, began to roll back the Viet Cong. The communists responded with a new strategy hammered out in a series of meetings in Hanoi in March 1973, according to the memoirs of Trần Văn Trà .
As the Viet Cong's top commander, Tra participated in several of these meetings. With U.S. bombings suspended, work on the Ho Chi Minh trail and other logistical structures could proceed unimpeded. Logistics would be upgraded until the North was in a position to launch a massive invasion of the South, projected for the 1975–76 dry season. Tra calculated that this date would be Hanoi's last opportunity to strike before Saigon's army could be fully trained.
In the November 1972 Election, Democratic nominee George McGovern lost 49 of 50 states to the incumbent President Richard Nixon . On 15 March 1973, President Nixon implied that the United States would intervene militarily if the communist side violated the ceasefire. Public and congressional reaction to Nixon's trial balloon was unfavorable and in April Nixon appointed Graham Martin as U.S. ambassador to Vietnam. Martin was a second stringer compared to previous U.S. ambassadors and his appointment was an early signal that Washington had given up on Vietnam. During his confirmation hearings in June 1973, Secretary of Defense James R. Schlesinger stated that he would recommend resumption of U.S. bombing in North Vietnam if North Vietnam launched a major offensive against South Vietnam. On 4 June 1973, the U.S. Senate passed the Case–Church Amendment to prohibit such intervention.
The oil price shock of October 1973 following the Yom Kippur War in Egypt caused significant damage to the South Vietnamese economy. The Viet Cong resumed offensive operations when the dry season began and by January 1974 it had recaptured the territory it lost during the previous dry season. After two clashes that left 55 South Vietnamese soldiers dead, President Thieu announced on 4 January that the war had restarted and that the Paris Peace Accord was no longer in effect. There had been over 25,000 South Vietnamese casualties during the ceasefire period. 
Gerald Ford took over as U.S. president on 9 August 1974 after President Nixon resigned due to the Watergate scandal . At this time, Congress cut financial aid to South Vietnam from $1 billion a year to $700 million. The U.S. midterm elections in 1974 brought in a new Congress dominated by Democrats who were even more determined to confront the president on the war. Congress immediately voted in restrictions on funding and military activities to be phased in through 1975 and to culminate in a total cutoff of funding in 1976.
The success of the 1973–74 dry season offensive inspired Trà to return to Hanoi in October 1974 and plead for a larger offensive in the next dry season. This time, Trà could travel on a drivable highway with regular fueling stops, a vast change from the days when the Ho Chi Minh trail was a dangerous mountain trek. Giáp, the North Vietnamese defense minister, was reluctant to approve Trà's plan. A larger offensive might provoke a U.S. reaction and interfere with the big push planned for 1976. Trà appealed over Giáp's head to first secretary Lê Duẩn , who approved of the operation.
Trà's plan called for a limited offensive from Cambodia into Phước Long Province . The strike was designed to solve local logistical problems, gauge the reaction of South Vietnamese forces, and determine whether U.S. would return to the fray.
On 13 December 1974, North Vietnamese forces attacked Route 14 in Phước Long Province . Phuoc Binh, the provincial capital, fell on 6 January 1975. Ford desperately asked Congress for funds to assist and re-supply the South before it was overrun. Congress refused. The fall of Phuoc Binh and the lack of an American response left the South Vietnamese elite demoralized.
The speed of this success led the Politburo to reassess its strategy. It was decided that operations in the Central Highlands would be turned over to General Văn Tiến Dũng and that Pleiku should be seized, if possible. Before he left for the South, Dũng was addressed by Lê Duẩn: "Never have we had military and political conditions so perfect or a strategic advantage as great as we have now."
At the start of 1975, the South Vietnamese had three times as much artillery and twice the number of tanks and armored cars as the opposition. They also had 1,400 aircraft and a two-to-one numerical superiority in combat troops over their Communist enemies.  However, the rising oil prices meant that much of this could not be used. They faced a well-organized, highly determined and well-funded North Vietnam. Much of the North's material and financial support came from the communist bloc. Within South Vietnam, there was increasing chaos. The departure of the American military had compromised an economy dependent on U.S. financial support and the presence of a large number of U.S. troops. South Vietnam suffered from the global recession that followed the Arab oil embargo .
On 10 March 1975, General Dung launched Campaign 275, a limited offensive into the Central Highlands, supported by tanks and heavy artillery. The target was Buôn Ma Thuột , in Đắk Lắk Province . If the town could be taken, the provincial capital of Pleiku and the road to the coast would be exposed for a planned campaign in 1976. The ARVN proved incapable of resisting the onslaught, and its forces collapsed on 11 March. Once again, Hanoi was surprised by the speed of their success. Dung now urged the Politburo to allow him to seize Pleiku immediately and then turn his attention to Kon Tum . He argued that with two months of good weather remaining until the onset of the monsoon, it would be irresponsible to not take advantage of the situation.
President Nguyễn Văn Thiệu , a former general, was fearful that his forces would be cut off in the north by the attacking communists; Thieu ordered a retreat. The president declared this to be a "lighten the top and keep the bottom" strategy. But in what appeared to be a repeat of Operation Lam Son 719 , the withdrawal soon turned into a bloody rout. While the bulk of ARVN forces attempted to flee, isolated units fought desperately. ARVN General Phu abandoned Pleiku and Kon Tum and retreated toward the coast, in what became known as the "column of tears".
As the ARVN tried to disengage from the enemy, refugees mixed in with the line of retreat. The poor condition of roads and bridges, damaged by years of conflict and neglect, slowed Phu's column. As the North Vietnamese forces approached, panic set in. Often abandoned by the officers, the soldiers and civilians were shelled incessantly. The retreat degenerated into a desperate scramble for the coast. By 1 April the "column of tears" was all but annihilated.
On 20 March, Thieu reversed himself and ordered Huế, Vietnam's third-largest city, be held at all costs, and then changed his policy several times. Thieu's contradictory orders confused and demoralized his officer corps. As the North Vietnamese launched their attack, panic set in, and ARVN resistance withered. On 22 March, the NVA opened the siege of Huế. Civilians flooded the airport and the docks hoping for any mode of escape. Some even swam out to sea to reach boats and barges anchored offshore. In the confusion, routed ARVN soldiers fired on civilians to make way for their retreat.
On 25 March, after a three-day battle, Huế fell. As resistance in Huế collapsed, North Vietnamese rockets rained down on Da Nang and its airport. By 28 March 35,000 VPA troops were poised to attack the suburbs. By 30 March 100,000 leaderless ARVN troops surrendered as the NVA marched victoriously through Da Nang. With the fall of the city, the defense of the Central Highlands and Northern provinces came to an end.
Final North Vietnamese offensive
With the northern half of the country under their control, the Politburo ordered General Dung to launch the final offensive against Saigon. The operational plan for the Ho Chi Minh Campaign called for the capture of Saigon before 1 May. Hanoi wished to avoid the coming monsoon and prevent any redeployment of ARVN forces defending the capital. Northern forces, their morale boosted by their recent victories, rolled on, taking Nha Trang, Cam Ranh, and Da Lat.
On 7 April, three North Vietnamese divisions attacked Xuân Lộc , 40 miles (64 km) east of Saigon. The North Vietnamese met fierce resistance at Xuân Lộc from the ARVN 18th Division , who were outnumbered six to one. For two bloody weeks, severe fighting raged as the ARVN defenders made a last stand to try to block the North Vietnamese advance. By 21 April, however, the exhausted garrison were ordered to withdraw towards Saigon.
An embittered and tearful president Thieu resigned on the same day, declaring that the United States had betrayed South Vietnam. In a scathing attack, he suggested U.S. Secretary of State Henry Kissinger had tricked him into signing the Paris peace agreement two years ago, promising military aid that failed to materialize. Having transferred power to Trần Văn Hương , he left for Taiwan on 25 April. At the same time, North Vietnamese tanks had reached Biên Hòa and turned toward Saigon, brushing aside isolated ARVN units along the way.
By the end of April, the ARVN had collapsed on all fronts except in the Mekong Delta . Thousands of refugees streamed southward, ahead of the main communist onslaught. On 27 April 100,000 North Vietnamese troops encircled Saigon. The city was defended by about 30,000 ARVN troops. To hasten a collapse and foment panic, the NVA shelled the airport and forced its closure. With the air exit closed, large numbers of civilians found that they had no way out.
Fall of Saigon
Chaos, unrest, and panic broke out as hysterical South Vietnamese officials and civilians scrambled to leave Saigon. Martial law was declared. American helicopters began evacuating South Vietnamese, U.S., and foreign nationals from various parts of the city and from the U.S. embassy compound. Operation Frequent Wind had been delayed until the last possible moment, because of U.S. Ambassador Graham Martin 's belief that Saigon could be held and that a political settlement could be reached.
Schlesinger announced early in the morning of 29 April 1975 the evacuation from Saigon by helicopter of the last U.S. diplomatic, military, and civilian personnel. Frequent Wind was arguably the largest helicopter evacuation in history. It began on 29 April, in an atmosphere of desperation, as hysterical crowds of Vietnamese vied for limited space. Martin pleaded with Washington to dispatch $700 million in emergency aid to bolster the regime and help it mobilize fresh military reserves. But American public opinion had soured on this conflict.
In the United States, South Vietnam was perceived as doomed. President Gerald Ford had given a televised speech on 23 April, declaring an end to the Vietnam War and all U.S. aid. Frequent Wind continued around the clock, as North Vietnamese tanks breached defenses on the outskirts of Saigon. In the early morning hours of 30 April, the last U.S. Marines evacuated the embassy by helicopter, as civilians swamped the perimeter and poured into the grounds. Many of them had been employed by the Americans and were left to their fate.
On 30 April 1975, NVA troops entered the city of Saigon and quickly overcame all resistance, capturing key buildings and installations. A tank from the 324th Division crashed through the gates of the Independence Palace at 11:30 am local time and the Viet Cong flag was raised above it. President Dương Văn Minh , who had succeeded Huong two days earlier, surrendered.
Other countries' involvement
People's Republic of China
In 1950, the People's Republic of China extended diplomatic recognition to the Viet Minh 's Democratic Republic of Vietnam and sent weapons, as well as military advisers led by Luo Guibo to assist the Viet Minh in its war with the French . The first draft of the 1954 Geneva Accords was negotiated by French prime minister Pierre Mendès France and Chinese Premier Zhou Enlai who, fearing U.S. intervention, urged the Viet Minh to accept a partition at the 17th parallel . 
China's support for North Vietnam included both financial aid and the deployment of hundreds of thousands of military personnel in support roles. In the summer of 1962, Mao Zedong agreed to supply Hanoi with 90,000 rifles and guns free of charge. Starting in 1965, China sent anti-aircraft units and engineering battalions to North Vietnam to repair the damage caused by American bombing, man anti-aircraft batteries, rebuild roads and railroads, transport supplies, and perform other engineering works. This freed North Vietnamese army units for combat in the South. China sent 320,000 troops and annual arms shipments worth $180 million.  The Chinese military claims to have caused 38% of American air losses in the war.  China claimed that its military and economic aid to North Vietnam and the Viet Cong totaled $20 billion (approx. $143 billion adjusted for inflation in 2015) during the Vietnam War.  Included in that aid were donations of 5 million tons of food to North Vietnam (equivalent to NV food production in a single year), accounting for 10-15% of the North Vietnamese food supply by the 1970s. 
Sino-Soviet relations soured after the Soviets invaded Czechoslovakia in August 1968. In October, the Chinese demanded North Vietnam cut relations with Moscow, but Hanoi refused.  The Chinese began to withdraw in November 1968 in preparation for a clash with the Soviets, which occurred at Zhenbao Island in March 1969. The Chinese also began financing the Khmer Rouge as a counterweight to the Vietnamese communists at this time.
China "armed and trained" the Khmer Rouge during the civil war and continued to aid them for years afterward.  The Khmer Rouge launched ferocious raids into Vietnam in 1975–1978. When Vietnam responded with an invasion that toppled the Khmer Rouge, China launched a brief, punitive invasion of Vietnam in 1979 .
Soviet ships in the South China Sea gave vital early warnings to Viet Cong forces in South Vietnam. The Soviet intelligence ships would pick up American B-52 bombers flying from Okinawa and Guam . Their airspeed and direction would be noted and then relayed to COSVN , North Vietnam's southern headquarters. Using airspeed and direction, COSVN analysts would calculate the bombing target and tell any assets to move "perpendicularly to the attack trajectory." These advance warning gave them time to move out of the way of the bombers, and, while the bombing runs caused extensive damage, because of the early warnings from 1968 to 1970 they did not kill a single military or civilian leader in the headquarters complexes.
The Soviet Union supplied North Vietnam with medical supplies, arms, tanks, planes, helicopters, artillery, anti-aircraft missiles and other military equipment. Soviet crews fired Soviet-made surface-to-air missiles at U.S. F-4 Phantoms , which were shot down over Thanh Hóa in 1965. Over a dozen Soviet citizens lost their lives in this conflict. Following the collapse of the Soviet Union in 1991, Russian officials acknowledged that the Soviet Union had stationed up to 3,000 troops in Vietnam during the war. 
Some Russian sources give more specific numbers: Between 1953 and 1991, the hardware donated by the Soviet Union included 2,000 tanks, 1,700 APCs , 7,000 artillery guns, over 5,000 anti-aircraft guns, 158 surface-to-air missile launchers, 120 helicopters. During the war, the Soviets sent North Vietnam annual arms shipments worth $450 million.   From July 1965 to the end of 1974, fighting in Vietnam was observed by some 6,500 officers and generals, as well as more than 4,500 soldiers and sergeants of the Soviet Armed Forces. In addition, Soviet military schools and academies began training Vietnamese soldiers – in all more than 10,000 military personnel. 
As a result of a decision of the Korean Workers' Party in October 1966, in early 1967 North Korea sent a fighter squadron to North Vietnam to back up the North Vietnamese 921st and 923rd fighter squadrons defending Hanoi. They stayed through 1968, and 200 pilots were reported to have served. 
In addition, at least two anti-aircraft artillery regiments were sent as well. North Korea also sent weapons, ammunition and two million sets of uniforms to their comrades in North Vietnam. Kim Il-sung is reported to have told his pilots to "fight in the war as if the Vietnamese sky were their own". 
The contribution to North Vietnam by the Republic of Cuba , under Fidel Castro have been recognized several times by representatives of the Democratic Republic of Vietnam.  Fidel Castro has mentioned in his discourses the Batallón Girón (Giron Battalion) as comprising the Cuban contingent that served as military advisors during the war.  In this battalion, alongside the Cubans, fought Nguyễn Thị Định , founding member of the Viet Cong, who later became the first female Major General in the North Vietnamese Army.  There are numerous allegations by former U.S. prisoners of war that Cuban military personnel were present at North Vietnamese prison facilities during the war and that they participated in torture activities, in what is known as the "Cuba Program".      Witnesses to this include Senator John McCain , 2008 U.S. Presidential candidate and former Vietnam prisoner of war, according to his 1999 book Faith of My Fathers .  Benjamin Gilman, a Vietnam War POW/MIA issue advocate, claim evidence that Cuba's military and non-military involvement may have run into the "thousands" of personnel.  Fidel Castro visited in person Quảng Trị province , held by North Vietnam after the Easter Offensive to show his support for the Viet Cong. 
On the anti-communist side, South Korea (a.k.a. the Republic of Korea, ROK) had the second-largest contingent of foreign troops in South Vietnam after the United States. In November 1961, Park Chung-hee proposed South Korean participation in the war to John F. Kennedy, but Kennedy disagreed. On 1 May 1964 Lyndon Johnson requested South Korean participation. The first South Korean troops began arriving in 1964 and large combat formations began arriving a year later. The ROK Marine Corps dispatched their 2nd Marine Brigade while the ROK Army sent the Capital Division and later the 9th Infantry Division . In August 1966 after the arrival of the 9th Division the Koreans established a corps command, the Republic of Korea Forces Vietnam Field Command, near I Field Force, Vietnam at Nha Trang .  The South Koreans soon developed a reputation for effectiveness, reportedly conducting counterinsurgency operations so well that American commanders felt that the South Korean area of responsibility was the safest. 
Approximately 320,000 South Korean soldiers were sent to Vietnam,  each serving a one-year tour of duty. Maximum troop levels peaked at 50,000 in 1968, however all were withdrawn by 1973.  About 5,099 South Koreans were killed and 10,962 wounded during the war. South Korea claimed to have killed 41,000 Viet Cong fighters.  The United States paid South Korean soldiers 236 million dollars for their efforts in Vietnam,  and South Korean GNP increased five-fold during the war. 
Australia and New Zealand
Australia and New Zealand, close allies of the United States and members of the Southeast Asia Treaty Organization (SEATO) and the ANZUS military co-operation treaty, sent ground troops to Vietnam. Both nations had gained experience in counterinsurgency and jungle warfare during the Malayan Emergency and World War II. Their governments subscribed to the Domino theory . Australia began by sending advisors to Vietnam in 1962, and combat troops were committed in 1965. New Zealand began by sending a detachment of engineers and an artillery battery, and then started sending special forces and regular infantry which were attached to Australian formations.  Australia's peak commitment was 7,672 combat troops and New Zealand's 552. More than 60,000 Australian personnel were involved during the course of the war, of which 521 were killed and more than 3,000 wounded.  Approximately 3,500 New Zealanders served in Vietnam, with 37 killed and 187 wounded.  Most Australians and New Zealanders served in the 1st Australian Task Force in Phước Tuy Province .
Some 10,450 Filipino troops were dispatched to South Vietnam. They were primarily engaged in medical and other civilian pacification projects. These forces operated under the designation PHLCAG-V or Philippine Civic Action Group-Vietnam. More noteworthy was the fact that the naval base in Subic Bay was used for the U.S. Seventh Fleet from 1964 till the end of the war in 1975.   The Navy base in Subic bay and the Air force base at Clark achieved maximum functionality during the war and supported an estimated 80,000 locals in allied tertiary businesses from shoe making to prostitution. 
Thai Army formations, including the "Queen's Cobra" battalion, saw action in South Vietnam between 1965 and 1971. Thai forces saw much more action in the covert war in Laos between 1964 and 1972, though Thai regular formations there were heavily outnumbered by the irregular "volunteers" of the CIA-sponsored Police Aerial Reconnaissance Units or PARU, who carried out reconnaissance activities on the western side of the Ho Chi Minh trail.
Republic of China (Taiwan)
Since November 1967, the Taiwanese government secretly operated a cargo transport detachment to assist the United States and South Vietnam. Taiwan also provided military training units for the South Vietnamese diving units, later known as the Lien Doi Nguoi Nhai (LDMN) or "Frogman unit" in English. In addition to the diving trainers there were several hundred military personnel. Military commandos from Taiwan were captured by communist forces three times trying to infiltrate North Vietnam.
Canada and the ICC
Canada, India and Poland constituted the International Control Commission , which was supposed to monitor the 1954 ceasefire agreement.  Officially, Canada did not have partisan involvement in the Vietnam War and diplomatically it was " non-belligerent ". Victor Levant suggested otherwise in his book Quiet Complicity: Canadian Involvement in the Vietnam War (1986).   The Vietnam War entry in The Canadian Encyclopedia asserts plainly that Canada's record on the truce commissions was a pro-Saigon partisan one. 
United Front for the Liberation of Oppressed Races (FULRO)
The ethnic minority peoples of south Vietnam like the Christian Montagnards (Degar), Hindu and Muslim Cham and the Buddhist Khmer Krom banded together in the United Front for the Liberation of Oppressed Races (French: Front Uni de Lutte des Races Opprimées, acronym: FULRO) to fight against the Vietnamese for autonomy or independence. FULRO fought against both the anti-Communist South Vietnamese and the Communist Viet Cong, and then FURLO proceeded to fight against the united Communist Socialist Republic of Vietnam after the fall of South Vietnam. FULRO was supported by China, the United States, Cambodia, and some French citizens.
During the war, the South Vietnamese President Ngo Dinh Diem began a program to settle ethnic Vietnamese Kinh on Montagnard lands in the Central Highlands region. This provoked a backlash from the Montagnards. The Cambodians under both the pro-China King Sihanouk and the pro-American Lon Nol supported their fellow co-ethnic Khmer Krom in south Vietnam, following an anti- ethnic Vietnamese policy.
FULRO was formed from the amalgation of the Cham organization "Champa Liberation Front" ( Front de Liberation du Champa FLC) led by the Cham Muslim officer Les Kosem who served in the Royal Cambodian Army, the Khmer Krom organization "Liberation Front of Kampuchea Krom" ( Front de Liberation du Kampuchea Krom FLKK) led by Chau Dara, a former monk, and the Montagnard organizations "Central Highlands Liberation Front" ( Front de Liberation des Hauts Plateaux FLHP) led by Y Bham Enuol and BAJARAKA.
After overthrowing pro-China Sihanouk, Cambodian leader Lon Nol, despite being anti-Communist and ostensibly in the "pro-American" camp, continued to back FULRO against all Vietnamese, both anti-communist South Vietnam and the Communist Viet Cong. Lon Nol planned a slaughter of all Vietnamese in Cambodia and a restoration of South Vietnam to a revived Champa state.
The leaders of FULRO were executed by the Khmer Rouge leader Pol Pot when he took power in Cambodia but FULRO insurgents proceeded to fight against the Vietnamese occupation of Cambodia and it was not until 1992 that they finally surrendered to the United Nations in Cambodia.
A large number of war crimes took place during the Vietnam War. War crimes were committed by both sides during the conflict and included rape, massacres of civilians, bombings of civilian targets, terrorism , the widespread use of torture and the murder of prisoners of war . Additional common crimes included theft, arson, and the destruction of property not warranted by military necessity . 
Allied war crimes
War crimes committed by US forces
In 1968, the Vietnam War Crimes Working Group (VWCWG) was established by the Pentagon task force set up in the wake of the My Lai Massacre , to attempt to ascertain the veracity of emerging claims of war crimes by U.S. armed forces in Vietnam, during the Vietnam War period.
The investigation compiled over 9,000 pages of investigative files, sworn statements by witnesses and status reports for top military officers, indicating that 320 incidents had factual basis.  The substantiated cases included 7 massacres between 1967 and 1971 in which at least 137 civilians were killed; seventy eight further attacks targeting non-combatants resulting in at least 57 deaths, 56 wounded and 15 sexually assaulted; one hundred and forty-one cases of US soldiers torturing civilian detainees or prisoners of war with fists, sticks, bats, water or electric shock.  Over 800 alleged atrocities were investigated but only 23 soldiers were ever convicted on charges and most served sentences of less than a year.  A Los Angeles Times report on the archived files concluded that the war crimes were not confined to a few rogue units, having been uncovered in every army division that was active in Vietnam. 
In 2003 a series of investigative reports by the Toledo Blade uncovered a large number of unreported American war crimes particularly from the Tiger Force unit.  Some of the most violent war criminals included men such as Sam Ybarra  and Sergeant Roy E. "the Bummer" Bumgarner, a soldier who served with the 1st Cavalry Division and later the 173d Airborne Brigade. 
In 1971 the later U.S. presidential candidate, John Kerry , testified before the U.S. Senate and stated that over 150 U.S. veterans testified during the Winter Soldier Investigation and described war crimes committed in Southeast Asia.
They told the stories of times that they had personally raped, cut off the ears, cut off heads, taped wires from portable telephones to human genitals and turned up the power, cut off limbs, blown up bodies, randomly shot at civilians, razed villages in a fashion reminiscent of Genghis Khan, shot cattle and dogs for fun, poisoned food stocks and generally ravaged the countryside of South Vietnam in addition to the normal ravage of war and the normal and very particular ravaging which is done by the applied bombing power of this country.— John Kerry testifying before the U.S. Senate in 1971
According to political scientist R.J. Rummel , U.S. troops murdered about 6,000 Vietnamese civilians during the war.  Nick Turse , in his 2013 book, Kill Anything that Moves , argues for a much higher total. He says that a relentless drive toward higher body counts, a widespread use of free-fire zones, rules of engagement where civilians who ran from soldiers or helicopters could be viewed as Viet Cong, and a widespread disdain for Vietnamese civilians led to massive civilian casualties and endemic war crimes inflicted by U.S. troops. One example cited by Turse is Operation Speedy Express , an operation by the 9th Infantry Division, which was described by John Paul Vann as, in effect, "many My Lais". A report by Newsweek magazine suggested that 5,000 innocent civilians may have been killed by U.S. soldiers in this single operation.  In more detail:
Air force captain, Brian Wilson, who carried out bomb-damage assessments in free-fire zones throughout the delta, saw the results firsthand. "It was the epitome of immorality…One of the times I counted bodies after an air strike—which always ended with two napalm bombs which would just fry everything that was left—I counted sixty-two bodies. In my report I described them as so many women between fifteen and twenty-five and so many children—usually in their mothers' arms or very close to them—and so many old people." When he later read the official tally of dead, he found that it listed them as 130 VC killed.
War Crimes committed by South Vietnamese forces
In terms of atrocities by the South Vietnamese, during the Diem era (1954-1963) R.J. Rummell estimated that 16,000 to 167,000 South Vietnamese civilians were killed; for 1964 to 1975, Rummel estimated a total of 42,000 to 128,000 killed. Thus, the total for 1954 to 1975 is from 57,000 to 284,000 deaths caused by South Vietnam, excluding NLF/North Vietnamese forces killed by the South Vietnamese armed forces. 
War crimes committed by South Korean forces
South Korean forces were also culpable of war crimes as well. One of the massacres was the Tây Vinh Massacre where ROK Capital Division of the South Korean Army killed 1,200 unarmed citizens between 12 February 1966 and 17 March 1966 in Bình An village, today Tây Vinh village, Tây Sơn District of Bình Định Province in South Vietnam.  Another example was the Gò Dài massacre where ROK Capital Division of the South Korean Army killed 380 civilians on 26 February 1966 in Gò Dài hamlet, in Bình An commune, Tây Sơn District (today Tây Vinh District) of Bình Định Province in South Vietnam. 
North Vietnamese, Viet Cong, and Khmer Rouge war crimes
According to Guenter Lewy, Viet Cong insurgents assassinated at least 37,000 civilians in South Vietnam and routinely employed terror. Ami Pedahzur has written that "the overall volume and lethality of Viet Cong terrorism rivals or exceeds all but a handful of terrorist campaigns waged over the last third of the twentieth century".  Notable Viet Cong atrocities include the massacre of over 3,000 unarmed civilians at Huế during the Tet Offensive and the incineration of hundreds of civilians at the Đắk Sơn massacre with flamethrowers.  Up to 155,000 refugees fleeing the final North Vietnamese Spring Offensive were killed or abducted on the road to Tuy Hòa in 1975.  According to Rummel, North Vietnamese and Viet Cong troops murdered between 106,000 and 227,000 civilians in South Vietnam.  North Vietnam was also known for its inhumane and abusive treatment of American POWs, most notably in Hỏa Lò Prison (aka the Hanoi Hilton ), where severe torture was employed to extract "confessions".
Viet Cong insurgents reportedly sliced off the genitals of village chiefs and sewed them inside their bloody mouths, cut off the tongues of helpless victims, rammed bamboo lances through one ear and out the other, slashed open the wombs of pregnant women, machine gunned children, hacked men and women to pieces with machetes, and cut off the fingers of small children who dared to get an education.  According to a U.S. Senate report, squads were assigned monthly assassination quotas.  Peer De Silva, former head of the Saigon department of the CIA, wrote that from as early as 1963, Viet Cong units were using disembowelment and other methods of mutilation for psychological warfare.
In the Cambodian Civil War , Khmer Rouge insurgents reportedly committed atrocities during the war. These include the murder of civilians and POWs by slowly sawing off their heads a little more each day,  the destruction of Buddhist wats and the killing of monks,  attacks on refugee camps involving the deliberate murder of babies and bomb threats against foreign aid workers,  the abduction and assassination of journalists,  and the shelling of Phnom Penh for more than a year.  Journalist accounts stated that the Khmer Rouge shelling "tortured the capital almost continuously", inflicting "random death and mutilation" on 2 million trapped civilians. 
The Khmer Rouge forcibly evacuated the entire city after taking it, in what has been described as a death march : François Ponchaud wrote: "I shall never forget one cripple who had neither hands nor feet, writhing along the ground like a severed worm, or a weeping father carrying his ten-year old daughter wrapped in a sheet tied around his neck like a sling, or the man with his foot dangling at the end of a leg to which it was attached by nothing but skin";  John Swain recalled that the Khmer Rouge were "tipping out patients from the hospitals like garbage into the streets….In five years of war, this is the greatest caravan of human misery I have seen." 
Women in the Vietnam War
During the Vietnam War, American women served on active duty doing a variety of jobs. Early in 1963, the Army Nurse Corps (ANC) launched Operation Nightingale, an intensive effort to recruit nurses to serve in Vietnam. Most nurses who volunteered to serve in Vietnam came from predominantly working or middle-class families with histories of military service. The majority of these women were white Catholics and Protestants.  Because the need for medical aid was great, many nurses underwent a concentrated four-month training program before being deployed to Vietnam in the ANC.  Due to the shortage of staff, nurses usually worked twelve-hour shifts, six days per week and often suffered from exhaustion. First Lieutenant Sharon Lane was the only female military nurse to be killed by enemy gunfire during the war, on 8 June 1969. 
At the start of the Vietnam War, it was commonly thought that American women had no place in the military. Their traditional place had been in the domestic sphere , but with the war came opportunity for the expansion of gender roles. In Vietnam, women held a variety of jobs which included operating complex data processing equipment and serving as stenographers.  Although a small number of women were assigned to combat zones, they were never allowed directly in the field of battle. The women who served in the military were solely volunteers. They faced a plethora of challenges, one of which was the relatively small number of female soldiers. Living in a male-dominated environment created tensions between the sexes. While this high male to female ratio was often uncomfortable for women, many men reported that having women in the field with them boosted their morale.  Although this was not the women's purpose, it was one positive result of their service. By 1973, approximately 7,500 women had served in Vietnam in the Southeast Asian theater.  In that same year, the military lifted the prohibition on women entering the armed forces.
American women serving in Vietnam were subject to societal stereotypes. Many Americans either considered females serving in Vietnam masculine for living under the army discipline, or judged them to be women of questionable moral character who enlisted for the sole purpose of seducing men.  To address this problem, the ANC released advertisements portraying women in the ANC as "proper, professional and well protected." (26) This effort to highlight the positive aspects of a nursing career reflected the ideas of second-wave feminism that occurred during the 1960s–1970s in the United States. Although female military nurses lived in a heavily male environment, very few cases of sexual harassment were ever reported. 
Unlike the American women who went to Vietnam, North Vietnamese women were enlisted and fought in the combat zone as well as providing manual labor to keep the Ho Chi Minh trail open and cook for the soldiers. They also worked in the rice fields in North Vietnam and Viet Cong-held farming areas in South Vietnam's Mekong Delta region to provide food for their families and the war effort. Women were enlisted in both the North Vietnamese Army (NVA) and the Viet Cong guerrilla insurgent force in South Vietnam. Some women also served for the North Vietnamese and Viet Cong intelligence services.
In South Vietnam, many women voluntarily served in the ARVN 's Women's Armed Force Corps (WAFC) and various other Women's corps in the military. Some, like in the WAFC, fought in combat with other soldiers. Others served as nurses and doctors in the battlefield and in military hospitals, or served in South Vietnam or America's intelligence agencies. During Diệm 's presidency, Madame Nhu was the commander of the WAFC. 
The war saw more than one million rural people migrate or flee the fighting in the South Vietnamese countryside to the cities, especially Saigon. Among the internal refugees were many young women who became the ubiquitous "bargirls" of wartime South Vietnam "hawking her wares – be that cigarettes, liquor, or herself" to American and allied soldiers.  American bases were ringed by bars and brothels. 
8,040 Vietnamese women came to the United States as war brides between 1964 and 1975.  Many mixed-blood Amerasian children were left behind when their American fathers returned to the United States after their tour of duty in South Vietnam. 26,000 of them were permitted to immigrate to the United States in the 1980s and 1990s. 
Black servicemen in Vietnam
The experience of African American military personnel during the Vietnam War has received significant attention. For example, the website "African-American Involvement in the Vietnam War" compiles examples of such coverage,  as does the print and broadcast work of journalist Wallace Terry .
The epigraph of Terry's book Bloods: An Oral History of the Vietnam War by Black Veterans (1984), includes the following quote: "I have an intuitive feeling that the Negro serviceman have a better understanding than whites of what the war is about." – General William C. Westmoreland , U.S. Army, Saigon, 1967. That book's introduction includes observations about the impact of the war on the black community in general and on black servicemen specifically. Points he makes on the latter topic include: the higher proportion of combat casualties in Vietnam among African American servicemen than among American soldiers of other races, the shift toward and different attitudes of black military careerists versus black draftees, the discrimination encountered by black servicemen "on the battlefield in decorations, promotion and duty assignments" as well as their having to endure "the racial insults, cross-burnings and Confederate flags of their white comrades" – and the experiences faced by black soldiers stateside, during the war and after America's withdrawal.  Upon the war's completion, black casualties made up 12.5% of US combat deaths, approximately equal to percentage of draft-eligible black men, though still slightly higher than the 10% who served in the military. 
The communist forces were principally armed with Chinese  and Soviet weaponry  though some guerrilla units were equipped with Western infantry weapons either captured from French stocks during the First Indochina war or from ARVN units or bought on the black market.  The ubiquitous Soviet AK-47 assault rifle was often regarded as the best rifle of the war, due to its ability to continue to function even in adverse, muddy conditions. Other weapons used by the Viet Cong included the World War II-era PPSh-41 submachine gun (both Soviet and Chinese versions), the SKS carbine, the DShK heavy machine gun and the RPG-2/B-40 grenade launcher.
While the Viet Cong had both amphibious tanks (such as the PT-76 ) and light tanks (such as the Type 62 ), they also used bicycles to transport munitions. The US' heavily armored, 90 mm M48A3 Patton tank saw extensive action during the Vietnam War and over 600 were deployed with US Forces. They played an important role in infantry support.
The US service rifle was initially the M14 (though some units were still using the WWII-era M1 Garand for a lack of M14s). Found to be unsuitable for jungle warfare, the M14 was replaced by M16 which was more accurate and lighter than the AK-47. For a period, the gun suffered from a jamming flaw known as "failure to extract", which means that a spent cartridge case remained lodged in the action after a round is fired.  According to a congressional report, the jamming was caused primarily by a change in gunpowder which was done without adequate testing and reflected a decision for which the safety of soldiers was a secondary consideration.  That issue was solved in early 1968 with the issuance of the M16A1 that featured a chrome plated chamber among several other features.  End-user satisfaction with the M16 was high except during this episode, but the M16 still has a reputation as a gun that jams easily.
The M60 machine gun GPMG (General Purpose Machine Gun) was the main machine gun of the US army at the time and many of them were put on helicopters, to provide suppressive fire when landing in hostile regions. The MAC-10 machine pistol was supplied to many special forces troops in the midpoint of the war. It also armed many CIA agents in the field.
Two aircraft which were prominent in the war were the AC-130 "Spectre" Gunship and the UH-1 "Huey" gunship. The AC-130 was a heavily armed ground-attack aircraft variant of the C-130 Hercules transport plane; it was used to provide close air support , air interdiction and force protection . The AC-130H "Spectre" was armed with two 20 mm M61 Vulcan cannons, one Bofors 40mm autocannon, and one 105 mm M102 howitzer . The Huey is a military helicopter powered by a single, turboshaft engine, with a two-bladed main rotor and tail rotor. Approximately 7,000 UH-1 aircraft saw service in Vietnam.
The Claymore M18A1 , an anti-personnel mine, was widely used during the war. Unlike a conventional land mine, the Claymore is command-detonated and directional, meaning it is fired by remote-control and shoots a pattern of 700 one-eighth-inch steel balls into the kill zone like a shotgun .
The aircraft ordnance used during the war included precision-guided munition , cluster bombs , and napalm , a thickening / gelling agent generally mixed with petroleum or a similar fuel for use in an incendiary device , initially against buildings and later primarily as an anti-personnel weapon that sticks to skin and can burn down to the bone.
The Vietnam War was the first conflict where U.S. forces had secure voice communication equipment available at the tactical level. The National Security Agency ran a crash program to provide U.S. forces with a family of security equipment code named NESTOR , fielding 17,000 units initially. Eventually 30,000 units were produced. However limitations of the units, including poor voice quality, reduced range, annoying time delays and logistical support issues led to only one unit in ten being used.  :Vol II, p.43 While many in the U.S. military believed that the Viet Cong and NVA would not be able to exploit insecure communications, interrogation of captured communication intelligence units showed they were able to understand the jargon and codes used in realtime and were often able to warn their side of impending U.S. actions.  :Vol II, pp. 4, 10
Events in Southeast Asia
On 2 July 1976, North and South Vietnam were merged to form the Socialist Republic of Vietnam .  Despite speculation that the victorious North Vietnamese would, in President Nixon's words, "massacre the civilians there [South Vietnam] by the millions," there is a widespread consensus that no mass executions in fact took place.  However, over the decade following the end of the war, an estimated 1 million South Vietnamese were sent to reeducation camps , with approximately 165,000 prisoners dying.   In addition, 200,000 to 400,000 Vietnamese boat people died at sea, according to the United Nations High Commissioner for Refugees . 
Phnom Penh , the capital of Cambodia, fell to the communist Khmer Rouge on 17 April 1975. Under the leadership of Pol Pot , the Khmer Rouge would eventually kill 1–3 million Cambodians in the Killing Fields , out of a population of around 8 million.  At least 1,386,734 victims of execution have been counted in mass graves, while demographic analysis suggests that the policies of the regime caused between 1.7 and 2.5 million excess deaths altogether (including disease and starvation).  After repeated border clashes in 1978, Vietnam invaded Democratic Kampuchea (Cambodia) and ousted the Khmer Rouge, who were being supported by China, in the Cambodian–Vietnamese War . In response, China invaded Vietnam in 1979. The two countries fought a brief border war, known as the Sino-Vietnamese War . From 1978 to 1979, some 450,000 ethnic Chinese left Vietnam by boat as refugees or were expelled. The devastating impact of Khmer Rouge rule contributed to a 1979 famine in Cambodia, during which an additional 300,000 Cambodians perished.
The Pathet Lao overthrew the monarchy of Laos in December 1975, establishing the Lao People's Democratic Republic under the leadership of a member of the royal family, Souphanouvong . The change in regime was "quite peaceful, a sort of Asiatic ' velvet revolution '"—although 30,000 former officials were sent to reeducation camps, often enduring harsh conditions for several years. The conflict between Hmong rebels and the Pathet Lao continued in isolated pockets. 
Over 3 million people left Vietnam, Laos, and Cambodia in the Indochina refugee crisis . Most Asian countries were unwilling to accept these refugees, many of whom fled by boat and were known as boat people .  Between 1975 and 1998, an estimated 1.2 million refugees from Vietnam and other Southeast Asian countries resettled in the United States, while Canada, Australia, and France resettled over 500,000. China accepted 250,000 people.  Of all the countries of Indochina, Laos experienced the largest refugee flight in proportional terms, as 300,000 people out of a total population of 3 million crossed the border into Thailand. Included among their ranks were "about 90 percent" of Laos's "intellectuals, technicians, and officials."  In 1988, Vietnam suffered a famine that afflicted millions.  Vietnam played a role in Asia similar to Cuba's in Latin America: it supported local revolutionary groups and was a headquarters for Soviet-style communism.  Unexploded ordnance , mostly from U.S. bombing, continue to detonate and kill people today. The Vietnamese government claims that ordnance has killed some 42,000 people since the war officially ended.   In 2012 alone, unexploded bombs and other ordnance claimed 500 casualties in Vietnam, Laos and Cambodia, according to activists and government databases. 
Agent Orange and similar chemical substances used by the U.S. have also caused a considerable number of deaths and injuries over the years, including the US Air Force crew that handled them. On 9 August 2012, the United States and Vietnam began a cooperative cleaning up of the toxic chemical on part of Danang International Airport , marking the first time Washington has been involved in cleaning up Agent Orange in Vietnam. 
Effect on the United States
|U.S. military costs||U.S. military aid to SVN||U.S. economic aid to SVN||Total||Total (2015 dollars)|
|$111 billion||$16.138 billion||$7.315 billion||$134.53 billion||$1.020 trillion|
In the post-war era, Americans struggled to absorb the lessons of the military intervention.  As General Maxwell Taylor , one of the principal architects of the war, noted, "First, we didn't know ourselves. We thought that we were going into another Korean War , but this was a different country. Secondly, we didn't know our South Vietnamese allies… And we knew less about North Vietnam. Who was Ho Chi Minh ? Nobody really knew. So, until we know the enemy and know our allies and know ourselves, we'd better keep out of this kind of dirty business. It's very dangerous."  President Ronald Reagan coined the term " Vietnam Syndrome " to describe the reluctance of the American public and politicians to support further international interventions after Vietnam.
Some have suggested that "the responsibility for the ultimate failure of this policy [America's withdrawal from Vietnam] lies not with the men who fought, but with those in Congress…"  Alternatively, the official history of the United States Army noted that " tactics have often seemed to exist apart from larger issues, strategies, and objectives. Yet in Vietnam the Army experienced tactical success and strategic failure… The…Vietnam War…legacy may be the lesson that unique historical, political, cultural, and social factors always impinge on the military…Success rests not only on military progress but on correctly analyzing the nature of the particular conflict, understanding the enemy's strategy, and assessing the strengths and weaknesses of allies. A new humility and a new sophistication may form the best parts of a complex heritage left to the Army by the long, bitter war in Vietnam."
U.S. Secretary of State Henry Kissinger wrote in a secret memo to President Gerald Ford that "in terms of military tactics, we cannot help draw the conclusion that our armed forces are not suited to this kind of war. Even the Special Forces who had been designed for it could not prevail."  Even Secretary of Defense Robert McNamara concluded that "the achievement of a military victory by U.S. forces in Vietnam was indeed a dangerous illusion."
Doubts surfaced as to the effectiveness of large-scale, sustained bombing. As Army Chief of Staff Harold Keith Johnson noted, "if anything came out of Vietnam, it was that air power couldn't do the job."  Even General William Westmoreland admitted that the bombing had been ineffective. As he remarked, "I still doubt that the North Vietnamese would have relented." 
The inability to bring Hanoi to the bargaining table by bombing also illustrated another U.S. miscalculation. The North's leadership was composed of hardened communists who had been fighting for thirty years. They had defeated the French, and their tenacity as both nationalists and communists was formidable. Ho Chi Minh is quoted as saying, "You can kill ten of my men for every one I kill of yours…But even at these odds you will lose and I will win."
The Vietnam War called into question the U.S. Army doctrine. Marine Corps General Victor H. Krulak heavily criticised Westmoreland's attrition strategy, calling it "wasteful of American lives… with small likelihood of a successful outcome."  In addition, doubts surfaced about the ability of the military to train foreign forces.
More than 3 million Americans served in the Vietnam War, some 1.5 million of whom actually saw combat in Vietnam.  James E. Westheider wrote that "At the height of American involvement in 1968, for example, there were 543,000 American military personnel in Vietnam, but only 80,000 were considered combat troops." Conscription in the United States had been controlled by the president since World War II, but ended in 1973.
By war's end, 58,220 American soldiers had been killed, more than 150,000 had been wounded, and at least 21,000 had been permanently disabled.  The average age of the U.S. troops killed in Vietnam was 23.11 years.  According to Dale Kueter, "Of those killed in combat, 86.3 percent were white, 12.5 percent were black and the remainder from other races."  Approximately 830,000 Vietnam veterans suffered some degree of posttraumatic stress disorder .  An estimated 125,000 Americans left for Canada to avoid the Vietnam draft,  and approximately 50,000 American servicemen deserted.  In 1977, United States president Jimmy Carter granted a full and unconditional pardon to all Vietnam-era draft dodgers .  The Vietnam War POW/MIA issue , concerning the fate of U.S. service personnel listed as missing in action , persisted for many years after the war's conclusion. The costs of the war loom large in American popular consciousness; a 1990 poll showed that the public incorrectly believed that more Americans lost their lives in Vietnam than in World War II . 
Impact on the U.S. military
As the Vietnam War continued inconclusively and became more unpopular with the American public, morale declined and disciplinary problems grew among American enlisted men and junior, non-career officers. Drug use, racial tensions, and the growing incidence of fragging —attempting to kill unpopular officers and non-commissioned officers with grenades or other weapons—created severe problems for the U.S. military and impacted its capability of undertaking combat operations. By 1971, a U.S. Army colonel writing in the Armed Forces Journal declared: "By every conceivable indicator, our army that now remains in Vietnam is in a state approaching collapse, with individual units avoiding or having refused combat, murdering their officers and non commissioned officers, drug-ridden, and dispirited where not near mutinous....The morale, discipline, and battleworthiness of the U.S. Armed Forces are, with a few salient exceptions, lower and worse than at any time in this century and possibly in the history of the United States." Between 1969 and 1971 the US Army recorded more than 700 attacks by troops on their own officers. Eighty-three officers were killed and almost 650 were injured. 
Ron Milam has questioned the severity of the "breakdown" of the U.S. armed forces, especially among combat troops, as reflecting the opinions of "angry colonels" who deplored the erosion of traditional military values during the Vietnam War. Although acknowledging serious problems, he questions the alleged "near mutinous" conduct of junior officers and enlisted men in combat. Investigating one combat refusal incident, a journalist declared, "A certain sense of independence, a reluctance to behave according to the military's insistence on obedience, like pawns or puppets...The grunts [infantrymen] were determined to survive...they insisted of having something to say about the making of decisions that determined whether they might live or die."
The morale and discipline problems and resistance to conscription (the draft) were important factors leading to the creation of an all-volunteer military force by the United States and the termination of conscription. The last conscript was inducted into the army in 1973.   The all-volunteer military moderated some of the coercive methods of discipline previously used to maintain order in military ranks.
Effects of U.S. chemical defoliation
One of the most controversial aspects of the U.S. military effort in Southeast Asia was the widespread use of chemical defoliants between 1961 and 1971. They were used to defoliate large parts of the countryside to prevent the Viet Cong from being able to hide their weapons and encampments under the foliage. These chemicals continue to change the landscape, cause diseases and birth defects, and poison the food chain. 
Early in the American military effort, it was decided that since the enemy were hiding their activities under triple-canopy jungle, a useful first step might be to defoliate certain areas. This was especially true of growth surrounding bases (both large and small) in what became known as Operation Ranch Hand . Corporations like Dow Chemical Company and Monsanto were given the task of developing herbicides for this purpose. American officials also pointed out that the British had previously used 2,4,5-T and 2,4-D (virtually identical to America's use in Vietnam) on a large scale throughout the Malayan Emergency in the 1950s in order to destroy bushes, crops, and trees in effort to deny communist insurgents the concealment they needed to ambush passing convoys. Indeed, Secretary of State Dean Rusk told President John F. Kennedy on 24 November 1961, that "[t]he use of defoliant does not violate any rule of international law concerning the conduct of chemical warfare and is an accepted tactic of war. Precedent has been established by the British during the emergency in Malaya in their use of aircraft for destroying crops by chemical spraying." 
The defoliants, which were distributed in drums marked with color-coded bands, included the " Rainbow Herbicides "— Agent Pink , Agent Green , Agent Purple , Agent Blue , Agent White , and, most famously, Agent Orange , which included dioxin as a by-product of its manufacture. About 12 million gallons (45,000,000 L) of Agent Orange were sprayed over Southeast Asia during the American involvement. A prime area of Ranch Hand operations was in the Mekong Delta , where the U.S. Navy patrol boats were vulnerable to attack from the undergrowth at the water's edge.
In 1961 and 1962, the Kennedy administration authorized the use of chemicals to destroy rice crops. Between 1961 and 1967, the U.S. Air Force sprayed 20 million U.S. gallons (75,700,000 L) of concentrated herbicides over 6 million acres (24,000 km 2 ) of crops and trees, affecting an estimated 13% of South Vietnam's land. In 1965, 42% of all herbicide was sprayed over food crops. Another purpose of herbicide use was to drive civilian populations into RVN-controlled areas.
Vietnamese victims affected by Agent Orange attempted a class action lawsuit against Dow Chemical and other US chemical manufacturers, but District Court Judge Jack B. Weinstein dismissed their case. They appealed, but the dismissal was cemented in February 2008 by the Court of Appeals for the Second Circuit . As of 2006, the Vietnamese government estimates that there are over 4,000,000 victims of dioxin poisoning in Vietnam, although the United States government denies any conclusive scientific links between Agent Orange and the Vietnamese victims of dioxin poisoning. In some areas of southern Vietnam, dioxin levels remain at over 100 times the accepted international standard. 
The U.S. Veterans Administration has listed prostate cancer , respiratory cancers , multiple myeloma , Diabetes mellitus type 2 , B-cell lymphomas , soft-tissue sarcoma , chloracne , porphyria cutanea tarda , peripheral neuropathy , and spina bifida in children of veterans exposed to Agent Orange. 
|Year||U.S. || South |
Estimates of the number of casualties vary, with one source suggesting up to 3.8 million violent war deaths in Vietnam for the period 1955 to 2002. 195,000–430,000 South Vietnamese civilians died in the war. Extrapolating from a 1969 US intelligence report, Guenter Lewy estimated 65,000 North Vietnamese civilians died in the war. Estimates of civilian deaths caused by American bombing of North Vietnam in Operation Rolling Thunder range from 52,000 to 182,000.  The military forces of South Vietnam suffered an estimated 254,256 killed between 1960 and 1974 and additional deaths from 1954–1959 and in 1975. The official US Department of Defense figure was 950,765 communist forces killed in Vietnam from 1965 to 1974. Defense Department officials believed that these body count figures need to be deflated by 30 percent. In addition, Guenter Lewy assumes that one-third of the reported "enemy" killed may have been civilians, concluding that the actual number of deaths of communist military forces was probably closer to 444,000. A detailed demographic study calculated 791,000–1,141,000 war-related deaths for all of Vietnam.  Between 240,000 and 300,000 Cambodians died during the war. About 60,000 Laotians also died, and 58,300 U.S. military personnel were killed,  of which 1,596 are still listed as missing as of 2015. 
The Vietnam War has been featured extensively in television, film, video games, and literature in the participant countries. In American popular culture, the "Crazy Vietnam Veteran", who was suffering from Posttraumatic stress disorder , became a common stock character after the war.
One of the first major films based on the Vietnam War was John Wayne 's pro-war film, The Green Berets (1968). Further cinematic representations were released during the 1970s and 1980s, including Michael Cimino 's The Deer Hunter (1978), Francis Ford Coppola 's Apocalypse Now (1979), Oliver Stone 's Platoon (1986) – based on his service in the U.S. Military during the Vietnam War, Stanley Kubrick 's Full Metal Jacket (1987), Hamburger Hill (1987), and Casualties of War (1989). Later films would include We Were Soldiers (2002) and Rescue Dawn (2007).
The war also influenced a generation of musicians and songwriters in Vietnam and the United States, both anti-war and pro/anti-communist. The band Country Joe and the Fish recorded "I-Feel-Like-I'm-Fixin'-To-Die Rag" / The "Fish" Cheer in 1965, and it became one of the most influential anti-Vietnam protest anthems. Many songwriters and musicians supported the anti-war movement, including Pete Seeger , Joan Baez , Peggy Seeger , Ewan MacColl , Barbara Dane , The Critics Group , Phil Ochs , John Lennon , Nina Simone , Neil Young , Tom Paxton , Jimmy Cliff and Arlo Guthrie .
- Aircraft losses of the Vietnam War
- Awards and decorations of the Vietnam War
- Battle of Quang Tri (1968)
- Counterculture of the 1960s
- Củ Chi tunnels
- Đắk Sơn massacre
- Draft lottery (1969)
- Kit Carson Scouts
- List of Medal of Honor recipients for the Vietnam War
- List of United States servicemembers and civilians missing in action during the Vietnam War (1968–69)
- McNamara Line
- Major General Michael D. Healy
- Operation Wheeler/Wallowa
- Patrol Craft Fast
- Protests of 1968
- The Sixties Unplugged
- United States Air Force in Thailand
- United States Army Special Forces in popular culture
- U.S. news media and the Vietnam War
- Vietnam War Crimes Working Group Files
- Weapons of the Cambodian Civil War
- Weapons of the Vietnam War
- Winter Soldier Investigation
- Due to the early presence of American troops in Vietnam the start date of the Vietnam War is a matter of debate. In 1998, after a high level review by the Department of Defense (DoD) and through the efforts of Richard B. Fitzgibbon's family the start date of the Vietnam War according to the US government was officially changed to 1 November 1955. U.S. government reports currently cite 1 November 1955 as the commencement date of the "Vietnam Conflict", because this date marked when the U.S. Military Assistance Advisory Group (MAAG) in Indochina (deployed to Southeast Asia under President Truman) was reorganized into country-specific units and MAAG Vietnam was established. Other start dates include when Hanoi authorized Viet Cong forces in South Vietnam to begin a low-level insurgency in December 1956, whereas some view 26 September 1959 when the first battle occurred between the Viet Cong and the South Vietnamese army, as the start date. 
- The figures of 58,220 and 303,644 for U.S. deaths and wounded come from the Department of Defense Statistical Information Analysis Division (SIAD), Defense Manpower Data Center, as well as from a Department of Veterans fact sheet dated May 2010  the CRS ( Congressional Research Service ) Report for Congress, American War and Military Operations Casualties: Lists and Statistics, dated 26 February 2010,  and the book Crucible Vietnam: Memoir of an Infantry Lieutenant.  Some other sources give different figures (e.g. the 2005/2006 documentary Heart of Darkness: The Vietnam War Chronicles 1945–1975 cited elsewhere in this article gives a figure of 58,159 U.S. deaths, and the 2007 book Vietnam Sons gives a figure of 58,226) 
- The Military Assistance Advisory Group, Indochina (with an authorized strength of 128 men) was set up in September 1950 with a mission to oversee the use and distribution of US military equipment by the French and their allies.
- The Việt Nam Quốc Dân Đảng had previously formed in Nanjing , China, at some point between August 1935 and early 1936 when the non-communist Vietnamese Nationalist Party ( Việt Nam Quốc Dân Đảng , or Viet Quoc), led by Nguyễn Thái Học , and some members of the Indochinese Communist Party (ICP) and a number of other Vietnamese nationalist parties formed an anti-imperialist united front. This organisation soon lapsed into inactivity, only to be revived by the ICP and Ho Chi Minh in 1941. 
- On 8 March 1965 the first American combat troops the, Third Marine Regiment, Third Marine Division , began landing in Vietnam to protect the Da Nang airport .