The Iran–Saudi Arabia proxy conflict, sometimes also referred to as the Iran–Saudi Arabia Cold War,^[68] Middle East Cold War^[69] or Middle East Conflict,^[70] is the ongoing struggle for influence in the Middle East and surrounding regions between the Islamic Republic of Iran and the Kingdom of Saudi Arabia.^[71] The two countries have provided varying degrees of support to opposing sides in nearby conflicts, including the civil wars in Syria,^[72][73][74] Yemen,^[75][76] and Iraq.^[77] The rivalry also extends to disputes in Bahrain,^[78] Lebanon,^[79] Qatar,^[80] Pakistan,^[81][82] Afghanistan,^[83][84] Nigeria,^[85][86] and Morocco,^[87] as well as broader competition in North and East Africa,^[86][88] parts of South Asia,^[89] Central Asia,^[90][84] and the Caucasus.^[91]

In what has been described as a cold war, the conflict is waged on multiple levels over geopolitical, economic, and sectarian influence in pursuit of regional hegemony.^[39][92][93] American support for Saudi Arabia and its allies as well as Russian and Chinese support for Iran and its allies have drawn comparisons to the dynamics of the Cold War era, and the proxy conflict has been characterized as a front in what Russian Prime Minister Dmitry Medvedev has referred to as the "New Cold War".^{[94][95][96][97]}

The rivalry today is primarily a political and economic struggle exacerbated by religious differences, and sectarianism in the region is exploited by both countries for geopolitical purposes as part of a larger conflict.^[93][98][99] Iran is largely Shia Muslim, while Saudi Arabia sees itself as the leading Sunni Muslim power.^[100]

The proxy conflict can be traced back to the Iranian Revolution in 1979, when the US-backed monarchic Imperial State of Iran became an Islamic republic. The revolutionaries called for the overthrow of monarchies and secular governments to be replaced with Islamic republics, much to the alarm of Iran's smaller Sunni-run Arab neighbors Saudi Arabia, Ba'athist Iraq, Kuwait, and the other Persian Gulf states, most of whom were monarchies and all of whom had sizable Shia populations. Islamist insurgents rose in Saudi Arabia in 1979, Egypt and Bahrain in 1981, Syria in 1982, and Lebanon in 1983.

Prior to the Iranian Revolution, the two countries constituted the Nixon Doctrine's "twin pillar" policy in the Middle East.^[101] The monarchies, particularly Iran since the US-led 1953 regime change, were allied with the US to ensure stability in the Gulf region and act as a bulwark against Soviet influence during the Arab Cold War between Saudi Arabia and Egypt under Gamal Abdel Nasser. The alliance acted as a moderating influence on Saudi-Iranian relations.^[102]

During this period Saudi Arabia styled itself as the leader of the Muslim world, basing its legitimacy in part on its control of the holy cities of Mecca and Medina. In 1962, it sponsored the inaugural General Islamic Conference in Mecca, at which a resolution was passed to create the Muslim World League. The organization is dedicated to spreading Islam and fostering Islamic solidarity under the Saudi purview, and has been successful in promoting Islam, particularly the conservative Wahhabi doctrine advocated by the Saudi government.^[103] Saudi Arabia also spearheaded the creation of the Organisation of Islamic Cooperation in 1969.

Saudi Arabia's image as the leader of the Muslim world was undermined in 1979 with the rise of Iran's new theocratic government under Ayatollah Khomeini, who challenged the legitimacy of the Al Saud dynasty and its authority as Custodian of the Two Holy Mosques.^[104][105] King Khalid initially congratulated Iran and stated that "Islamic solidarity" could be the basis of closer relations between the two countries, but relations worsened substantially over the next decade. In response to the 1987 Mecca incident in which Shia pilgrims clashed with Saudi security forces during the Hajj, Khomeini stated: "These vile and ungodly Wahhabis, are like daggers which have always pierced the heart of the Muslims from the back...Mecca is in the hands of a band of heretics."^[106] Iran also called for the ouster of the Saudi government.^[107]

In 1980, Saddam Hussein attempted to take advantage of revolutionary unrest in Iran and quell the revolution in its infancy. Fearing a possible revolutionary wave that could threaten Iraq's stability and embolden its Shia population, Saddam launched an invasion on 20 September, triggering the Iran–Iraq War which lasted for eight years and killed hundreds of thousands. Saddam had reportedly secured Saudi support for Iraq's war effort during an August 1980 visit he made to Saudi Arabia.^[108] This was in addition to financial and military support Iraq received from neighboring leaders in Saudi Arabia, Egypt, Kuwait, Jordan, Qatar, and the United Arab Emirates, in part to hedge Iranian power and prevent the spread of its revolution.

American support for Iraq during the war had profound effects on Iran. The United States' defense of Saddam and its role in blocking investigations into Iraq's use of chemical weapons on Iranian soldiers and civilians convinced Iran to further pursue its own unconventional weapons program. The government has also used American hostility to justify foreign and domestic policies, including its nuclear program and crackdowns on internal dissent.^[109]

Apart from the Iran–Iraq War, Iran and Saudi Arabia engaged in tense competition elsewhere, supporting opposing armed groups in the Lebanese Civil War, the Soviet–Afghan War, and other conflicts. After the Cold War, Iran and Saudi Arabia continued to support different groups and organizations along sectarian lines such as in Afghanistan, Yemen, and Iraq.^{[110][111][112]}

The current phase of the conflict began in 2011 when the Arab Spring sparked a revolutionary wave across the Middle East and North Africa, leading to revolutions in Tunisia, Egypt, and Yemen, and the outbreak of civil war in Libya and Syria. The Arab Spring in 2011 destabilized three major regional actors, Iraq, Syria and Egypt, creating a power void.^[113] These uprisings across the Arab world caused political instability throughout the region. In response, Saudi Arabia called for the formation of a Gulf Union to deepen ties among the member states of the Gulf Cooperation Council (GCC), a political and economic bloc founded in 1981. The proposal reflected the Saudi government's preoccupation with preventing potential uprisings by disenfranchised minorities in the Gulf monarchies as well as its regional rivalry with Iran.^[114] The union would have centralized Saudi influence in the region by giving it greater control over military, economic, and political matters affecting member states. With the exception of Bahrain, members rejected the proposed federation, as Oman, Qatar, Kuwait, and the United Arab Emirates were wary that it would lead to Saudi dominance.^[115]

Due to the decreasing importance of the Israeli–Palestinian conflict as a wedge issue and mutual tensions with Iran, GCC states have sought strengthened economic and security cooperation with Israel, who is involved in its own proxy conflict with Iran.^[116] Saudi Arabia has also become increasingly concerned about the United States' commitment as an ally and security guarantor. The American foreign policy pivot to Asia, its lessening reliance on Saudi oil, and the potential of rapprochement with Iran have all contributed to a more assertive Saudi foreign policy.^[40] In 2015 Saudi Arabia formed the intergovernmental Islamic Military Alliance to Fight Terrorism (IMAFT) in December 2015 with the stated goal of combating terrorism. The coalition currently comprises 41 member states, all of which are led by Sunni-dominated governments. Shia-led Iran, Iraq, and Syria are notably excluded, something which has drawn concerns that the initiative is part of the Saudi effort to isolate Iran.^[117][118]

The onset of the Arab Winter exacerbated Saudi concerns about Iran as well as its own internal stability. This prompted Riyadh to take greater action to maintain the status quo, particularly within Bahrain and other bordering states, with a new foreign policy described as a "21st century version of the Brezhnev Doctrine".^[119][120] Iran took the opposite approach in the hope of taking advantage of regional instability by expanding its presence in the Shia crescent and creating a land corridor of influence stretching from Iraq to Lebanon, done in part by supporting Shia militias in the war against ISIL.^[121][122]

While they all share concern over Iran, the Sunni Arab governments both within and outside of the GCC have long disagreed on political Islam. Saudi Arabia's Wahhabi religious establishment and its top-down bureaucracy differ from some of its allies such as Qatar, which promotes populist Sunni Islamist platforms similar to that of President Recep Tayyip Erdoğan in Turkey. Qatar has also drawn criticism from neighboring Sunni countries for its support of controversial transnational organizations like the Muslim Brotherhood, which as of 2015 is considered a terrorist organization by the governments of Bahrain, Egypt, Russia, Syria, Saudi Arabia, and the United Arab Emirates.^[123] The United Arab Emirates, on the other hand, supports anti-Islamist forces in Libya, Egypt, Yemen and other countries, and is focused more on domestic issues, similar to Egypt under President Abdel Fattah el-Sisi. These differences make it unlikely that the Sunni world could unite against both Iran and terrorism, despite shared opposition.^[124] Since King Salman came to power in 2015, Saudi Arabia has increasingly moved from its traditional Wahhabist ideological approach to a nationalist one, and has adopted a more aggressive foreign policy.^[125]

The complex nature of economic and security concerns, ideological division, and intertwined alliances has also drawn comparisons to pre-World War I Europe.^[126] The conflict also shares similarities with the Arab Cold War between Egypt and Saudi Arabia in the 1950s and 1960s. Influence was judged by each state's ability to affect the affairs of neighboring countries, non-state actors played significant roles, and disunity in both camps led to tactical alliances between states on opposing sides.^[69][127]

The 2015 Mina stampede in Mecca during the annual Hajj pilgrimage further inflamed tensions. Tehran blamed the Saudi government for the tragedy and accused them of incompetence, which Riyadh rejected.^{[128][129][130]} In May 2016 Iran suspended participation in the upcoming Hajj.^[131] In September, Saudi Arabia launched a 24-hour Persian language satellite channel to broadcast the Hajj proceedings from 10 to 15 September. Ayatollah Khamenei accused Riyadh of politicizing the Hajj tragedy and argued that Saudi Arabia should not be running the pilgrimage.^[132][133]

On 2 January 2016, 47 people were put to death in several Saudi cities, including prominent Shiite cleric Nimr al-Nimr. Protesters of the executions responded by demonstrating in Iran’s capital, Tehran. That same day a few protesters would eventually ransack the Saudi Embassy in Tehran and later set it ablaze.^[134] Police donned riot gear and arrested 40 people during the incident.^{[135][136][137]} In response, Saudi Arabia, along with its allies, Bahrain, Sudan, Djibouti, Somalia, and the Comoros cut diplomatic ties with Iran.^[138][139] Iran's foreign ministry responded by saying the Saudis were using the incident as a pretext for fueling tensions.^[140]

In recent years, King Salman made significant changes in domestic policy to address growing unemployment and economic uncertainty.^[141] Such economic pressures further affected the regional dynamic in 2016. Russia, who has long maintained ties with Iran, has also sought closer ties to Saudi Arabia. In September 2016, the two nations conducted informal talks about cooperating on oil production. Both have been heavily affected by the collapse of oil prices and considered the possibility of an OPEC freeze on oil output. As part of the talks, Russian President Vladimir Putin recommended an exemption for Iran, whose oil output has steadily increased following the lifting of international sanctions in January 2016. He stated that Iran deserves the opportunity to reach its pre-sanction levels of output.^[142][143] In what was seen as a significant compromise, Saudi Arabia offered to reduce its oil production if Iran capped its own output by the end of 2016.^[144]

Extremist movements throughout the Middle East have also become a major division between Iran and Saudi Arabia. During the Cold War, Saudi Arabia funded extremist militants in part to bolster resistance to the Soviet Union at the behest of the United States, and later to combat Shia movements supported by Iran. The support had the unintended effect of metastasizing extremism throughout the region. The Saudi government now considers extremist groups like ISIL and the Al-Nusra Front to be one of the two major threats to the kingdom and its monarchy, the other being Iran.^[145] In a New York Times op-ed, Iranian Foreign Minister Mohammad Javad Zarif agreed that terrorism was an international threat and called on the United Nations to block funding of extremist ideologies using Iran's WAVE initiative as a framework. However, he placed the blame on Saudi Arabia and its sponsorship of Wahhabism for instability in the Middle East. He argued that Wahhabism was the fundamental ideology shared among terrorist groups in the Middle East, and that it has been "devastating in its impact". He went so far as to proclaim "Let us rid the world of Wahhabism" and asserted that, despite arguments otherwise, Wahhabism was the true cause of the Iran–Saudi Arabia rivalry.^[146]

The election of Donald Trump in the United States in 2016 prompted uncertainty from both countries about future US policy in the Middle East, as both were targets of criticism during his campaign. The Saudi government anticipated that the Trump administration would adopt a more hawkish stance than the Obama administration on Iran, which would potentially benefit Riyadh.^[147] Iran feared the return of economic isolation, and President Hassan Rouhani made efforts to establish further international economic participation for the country by signing oil deals with Western companies before Trump took office.^[148]

In May 2017, Trump declared a shift in US foreign policy toward favoring Saudi Arabia at Iran's expense, marking a departure from President Obama's more reconciliatory approach. This move came days after the re-election of Rouhani in Iran, who defeated conservative candidate Ebrahim Raisi. Rouhani's victory was seen as a popular mandate for liberal reforms in the country.^[149]

Several incidents in mid-2017 further heightened tensions. In May 2017, Saudi forces laid siege on Al-Awamiyah, the home of Nimr al-Nimr, in a clash with Shia militants.^[150] Dozens of Shia civilians were reportedly killed. Residents are not allowed to enter or leave, and military indiscriminately shells the neighborhoods with artillery fire and snipers are reportedly shooting residents.^{[151][152][153]} In June, the Iranian state-owned news agency Press TV reported that the president of a Quran council and two cousins of executed Nimr al-Nimr were killed by Saudi security forces in Qatif.^[154][155] During the subsequent crackdown the Saudi government demolished several historical sites and many other buildings and houses in Qatif.^[156] On 17 June, Iran announced that the Saudi coast guard had killed an Iranian fisherman.^[157][158] Soon after, Saudi authorities captured three Iranian citizens who they claimed were IRGC members plotting a terrorist attack on an offshore Saudi oilfield.^[159] Iran denied the claim, saying that those captured are regular fishermen and demanding their immediate release.^[160]

In the wake of the June 2017 Tehran attacks committed by ISIL militants, the Iranian Revolutionary Guard Corps issued a statement blaming Saudi Arabia, while Saudi Foreign Minister Adel al-Jubeir said there was no evidence that Saudis were involved.^[161] Later Iranian official Hossein Amir-Abdollahian stated that Saudi Arabia is the prime suspect behind the Tehran attacks.^[162] The commander of IRGC, Major General Mohammad Ali Jafari, claimed that Iran has intelligence proving Saudi Arabia's, Israel's, and the United States' involvement in the Tehran attack.^[163] Iran's Supreme Leader Ayatollah Khamenei later accused the United States of creating ISIL and of joining Saudi Arabia in funding and directing ISIL in addition to other terrorist organizations.^[164]

In October 2017, the government of Switzerland announced an agreement in which it would represent Saudi interests in Iran and Iranian interests in Saudi Arabia. The two countries had severed relations in January 2016.^[165]

Several major developments occurring in November 2017 drew concerns that that proxy conflict might escalate into a direct military confrontation between Iran and Saudi Arabia.^[68][166] On 4 November the Royal Saudi Air Defense intercepted a ballistic missile over Riyadh International Airport. Foreign Minister Adel al-Jubeir asserted that the missile was supplied by Iran and launched by Hezbollah militants from territory held by Houthi rebels in Yemen. Crown Prince Mohammad bin Salman called it "direct military aggression by the Iranian regime" and said that it "may be considered an act of war against the kingdom".^[167] Also on 4 November, the Prime Minister of Lebanon resigned, sparking a political crisis seen as part of a Saudi effort to counteract Iran's influence in the country. Bahrain also blamed a 10 November explosion on its main oil pipeline on Iran.^[168]

On 24 November 2017, Dubai's security chief Lieutenant General Dhahi Khalfan blamed the 2017 Sinai attack on Al-Jazeera and called for bombing of the network by a Saudi-led coalition.^[169] In late November 2017, IRGC commander Jafari said revolutionary Islamic paramilitary forces had formed across the Middle East and surrounding regions to counter the influence of ultraconservative militant jihadi groups and Western powers.^[170]

In 2017 Saudi Arabia funded the creation of the Persian language satellite TV station Iran International, operated from London.^[171]

Saudi Arabia under King Salman has adopted a more assertive foreign policy, particularly reflected in the country's intervention in Yemen in 2015 and its involvement in Lebanon in 2017. This has continued with the June 2017 appointment of Mohammad bin Salman as Crown Prince, who has been considered the power behind the throne for years.^{[172][173][174]} The Crown Prince has referred to Iran, Turkey, and Islamic extremist groups as a "triangle of evil," and compared Supreme Leader Khamenei to Adolf Hitler.^[175][176] The populist, anti-Iranian rhetoric comes at a time of uncertainty over potential fallout from Mohammad bin Salman's consolidation of power, and he has used the rivalry as a means to strengthen Saudi nationalism despite the country's domestic challenges.^[125]

As part of the Saudi Vision 2030 plan, Mohammad bin Salman is pursuing American investment to aid efforts to diversify Saudi Arabia's economy away from oil.^[177][176] The reforms also include moving the country away from Wahhabi conservatism, which the Crown Prince discussed in 2017: "What happened in the last 30 years is not Saudi Arabia. What happened in the region in the last 30 years is not the Middle East. After the Iranian revolution in 1979, people wanted to copy this model in different countries, one of them is Saudi Arabia. We didn't know how to deal with it. And the problem spread all over the world. Now is the time to get rid of it."^[178]

Both Israel and Saudi Arabia supported the US withdrawal from the Iran nuclear deal.^[177][179] In anticipation of the withdrawal, Iran indicated it would continue to pursue closer ties to Russia and China, with Ayatollah Khamenei stating in February 2018: "In foreign policy, the top priorities for us today include preferring East to West."^[180] The unilateral decision by the United States drew concerns of increased tensions with Russia and China, both of which are parties to the nuclear agreement.^[179] It also heightened tensions in the Middle East, raising the risk of a larger military conflict breaking out involving Israel, Saudi Arabia, and Iran.^[181][182]

The United States reinstated sanctions against Iran in August 2018 despite opposition from European allies.^[183] The Trump administration also pushed for a military alliance with Sunni Arab states to act as a bulwark against Iran. The plan in consideration would establish a "Middle East Strategic Alliance" with six GCC states in addition to Jordan and Egypt.^[184]

The assassination of Jamal Khashoggi prompted international backlash against Saudi Arabia and Mohammad bin Salman.^[185] The Trump administration issued a statement reiterating its support for Saudi Arabia and blaming Iran for the war in Yemen.^[186] The United States Senate responded to the president by passing bipartisan resolutions condemning the assassination and voting to end United States aid to Saudi Arabia for the war in Yemen, though the measures were considered largely symbolic.^[187]

Military tensions between Iran and the United States escalated in 2019 amid a series of confrontations involving the US, Iran, and Saudi Arabia. Attacks on oil tankers in the Gulf of Oman took place in May and June.^[188][189] In the wake of growing tensions, Foreign Minister Javad Zarif stated that Iran sought good relations with Saudi Arabia, the United Arab Emirates, and their allies, and called on them to end their dispute with Qatar.^[190]

In September 2019 a drone attack was launched on the Saudi Aramco oil processing facility in Abqaiq and Khurais oil field in the Eastern Province of Saudi Arabia. The attack knocked out half of the country's oil supply.^[191] Although the Houthi rebels in Yemen claimed responsibility, the US Secretary of State Mike Pompeo alleged that Iran was behind the attack, a charge which Iran denied.^[192] Saudi Arabia and the US were reportedly investigating whether the attacks involved cruise missiles launched from Iran or Iraq. US officials had previously concluded that the attack on the East-West pipeline was launched by Iranian-backed militias in southern Iraq, despite Houthi rebels also claiming responsibility.^[193] On 16 September, the US told Saudi Arabia that it had concluded that Iran was a staging ground for the September attack. The US raised the prospect of a joint retaliatory strike on Iran, an action which would potentially broaden into a regional conflict.^[194] Saudi Arabia said its investigation was ongoing, but officials alleged that Iranian weapons were used in the strikes and that the attacks were not launched from Yemen. The claims were made without supporting evidence.^[195] Iran's Hassan Rouhani, after the attack on Aramco, claimed that the Saudi Arabia should take it as a warning to stop its intervention in Yemen. The Saudi-led intervention has led to the deaths of more than thousands till date.^[196]

The Gulf Cooperation Council, an alliance of Sunni Arab States of the Gulf region including Saudi Arabia, has often been described as a Saudi headed alliance to counter Iran, which engaged pro-Saudi interests in Bahrain.^[41]

MEK, a long existing rebel Iranian group has received an increasing support from Saudi Arabia.^[5][6]

Saudi Arabia has allegedly provided support to the Kurdish militants within the KDPI and PAK through its consulate in Erbil, the capital of the Kurdistan Regional Government in Iraqi Kurdistan.^[197]

The rebel group Jaish ul-Adl, active in the Sistan and Baluchestan region of Iran, was accused by Iranian authorities of receiving Saudi support.^[10]

The speaker of Iran's parliament, Ali Larijani, stated that Saudi Arabia gave "strategic" intelligence information to Israel during the 2006 Lebanon War.^[198] In May 2018, Israeli defense minister Avigdor Lieberman supported greater discussion between Israel, Saudi Arabia and the Gulf states, stating "It's time for the Middle East to [...] have an axis of moderate countries," opposed to the network of Iranian allies and proxies.^[181] As of 2018, several sources described alleged intelligence ties between Saudi Arabia and Israel as a "covert alliance", with a joint interest to counter Iran in the region.^[199] The New York Times remarked that such cooperation was made more difficult by controversy over Israel's attitude towards Palestinians.^[200]

US Secretary of State Mike Pompeo denounced the attacks on the Saudi oil industry, on September 14 2019, as an “act of war”. President Donald Trump called for an increase in sanctions against Iran opposing the strikes.^[201]

Syria

Qatar–Saudi Arabia relations have been strained since the beginning of the Arab Spring.^[203] Qatar has been a focus of controversy in the Saudi-Iranian rivalry due to Saudi Arabia's longstanding concern about the country's relationship with Iran and Iranian-backed militant groups.^[204]

In June 2017, Saudi Arabia, the United Arab Emirates, Bahrain, Egypt, the Maldives, Mauritania, Sudan, Senegal, Djibouti, Comoros, Jordan, the Tobruk-based Libyan government, and the Hadi-led Yemeni government severed diplomatic relations with Qatar and blocked their airspace and sea routes, in addition to Saudi Arabia blocking the only land crossing. The reasons cited were Qatar's relations with Iran, Al-Jazeera's coverage of other GCC states and Egypt, and Qatar's alleged support of Islamist groups.^[205][206] Qatar was also expelled from the anti-Houthi coalition.^[207] Qatar's defense minister Khalid bin Mohammed Al Attiyah called the blockade akin to a bloodless declaration of war, and Qatar's finance minister Ali Sharif Al Emadi stated that Qatar was rich enough to withstand the blockade.^[208][209]

The bloc sought a guarantee that Qatar will in the future align in all matters with other Gulf states, discuss all of its decisions with them, and provide regular reports on its activity (monthly for the first year, quarterly for the second, and annually for the following ten years). They also demanded the deportation of all political refugees who live in Qatar to their countries of origin, freezing their assets, providing any desired information about their residency, movements, and finances, and revoking their Qatari citizenship if naturalized. They also demanded that Qatar be forbidden from granting citizenship to any additional fugitives.^[210][211] Upon Qatar's rejection of these demands, the countries involved announced that the blockade would remain in place until Qatar changed its policies.^[212][213] On 24 August 2017, Qatar announced that they would restore full diplomatic relations with Iran.^[214]

Russia has been aligned with Iran and Syria for years. It intervened in Syria to provide support for the Assad government and to target rebel groups, working together with Iran and using Iranian air bases to stage air strikes.^[215] It also joined Iran, Iraq, and Syria in forming a joint intelligence-sharing coalition as part of the fight against ISIL.^[216] The alliance coincided with the US-led coalition created a year earlier to fight ISIL. The competing military actions were seen as part of a larger proxy conflict between the United States and Russia.^{[217][218][219]}

In a conversation with King Salman in March 2018, Chinese President Xi Jinping expressed interest in increased strategic cooperation with Saudi Arabia. Although it has traditionally stayed out of the conflict despite relying on the region for oil, China has recently played both sides, and has had ties with Tehran for years.^[96][97] Although it has warm relations with the Assad government, China has not involved itself in the Syrian Civil War, instead supporting the Russian-led peace process and investing in Syria's reconstruction.^[220] China's increased involvement in the region has come at a time when Xi Jinping has sought to expand China's global influence.^[221]

Syria has been a major theater in the proxy conflict throughout its ongoing civil war, which began in 2011. Iran and the GCC states have provided varying degrees of military and financial support to opposing sides, with Iran backing the government and Saudi Arabia supporting rebel militants.

Syria is an important part of Iran's sphere of influence, and the government under Bashar al-Assad has long been a major ally. During the early stages of the Arab Spring, Supreme Leader Khamenei initially expressed support for the revolutions in Tunisia and Egypt, characterizing them as an "Islamic awakening" akin to its own revolution in 1979. When protests broke out in Syria, Iran changed its position and condemned them, comparing the uprising to its own presidential election protests in 2009 and accusing the United States and Israel of being behind the unrest.^[222]

The war threatens Iran's position, and Saudi Arabia and its allies have sided with Sunni rebels in part to weaken Iran. For years Iranian forces have been involved on the ground, with soldiers in Islamic Revolutionary Guards Corps facing heavy casualties.^[223] In 2014, with no end in sight to the conflict, Iran increased its ground support for the Syrian Army, providing elite forces, intelligence gathering, and training. Iran also backs pro-Assad Hezbollah fighters.^[224] Although Iran and Saudi Arabia agreed in 2015 to participate in peace talks in Vienna in participation with United States Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov, the talks ultimately failed.^[225]

Saudi Arabia countered Russia's intervention in Syria by increasing its support for the rebels and supplying American-made anti-tank TOW missiles, a move which slowed initial progress made by Russian and Syrian forces.^[226]

Yemen has been called one of the major fronts in the conflict as a result of the revolution and subsequent civil war.^[227][228] Yemen had for years been within the Saudi sphere of influence. The decade-long Houthi insurgency in Yemen stoked tensions with Iran, with accusations of covert support for the rebels. A 2015 UN report alleged that Iran provided the Houthi rebels with money, training, and arms shipments beginning in 2009.^[229] However, the degree of support has been subject to debate, and accusations of greater involvement have been denied by Iran.^{[230][231][232]} The 2014–2015 coup d'état was viewed by Saudi leadership as an immediate threat, and as an opportunity for Iran to gain a foothold in the region. In March 2015, a Saudi-led coalition of Arab states, including all GCC members except Oman, intervened and launched airstrikes and a ground offensive in the country, declaring the entire Saada Governorate a military target and imposing a naval blockade.^[233]

The United States intervened in October 2016 after missiles were fired at a US warship, which was in place to protect oil shipments along the sea lane passing through the Mandeb Strait. The US blamed the rebels and responded by targeting radar sites with missile strikes along the Red Sea coast. In response, rebels called the strikes evidence of American support for the Saudi campaign.^[234][235]

While the majority of Muslims in Iraq are Shia, the country has been ruled for decades by Sunni-dominated governments under the Ottoman Empire, the British-installed Hashemites, and the Ba'athists. Under the rule of Saddam Hussein, Iraq was hostile to both Iran and Saudi Arabia and acted as a counterbalancing regional power. The American-led invasion in 2003 caused a power vacuum in the region. With the antagonistic Ba'athist regime removed, Iran sought a more friendly Shia-dominated government and supported sympathetic rebel factions as part of an effort to undermine the coalition, which Iran feared would install a government hostile to its interests.^[236]

Saudi Arabia remained more passive during the occupation of Iraq, taking caution to preserve its relations with the United States by avoiding any direct support of Sunni insurgent groups. Riyadh supported the Bush administration's commitment to stay in the country, as it limited Iran's influence.^[237] The edicts issued in May 2003 by Coalition Provisional Authority Administrator Paul Bremer to exclude members of the Ba'ath Party from the new Iraqi government and to disband the Iraqi Army undermined the occupation effort. The orders empowered various insurgent factions and weakened the new government's functional capabilities, leaving Iraq vulnerable to future instability.^[238]

Following the United States withdrawal from Iraq in December 2011, the country drifted further into Iran's sphere of influence. The instability that resulted from the Iraqi Civil War and the rise of ISIL threatened the existence of the Iraqi regime and led to an Iranian intervention in 2014. Iran mobilized Shia militia groups to halt and ultimately push back the advancing Sunni insurgency,^[239] though the resurgence of ISIL in Iraq remains more than a possibility.^[240]

The Iraqi government remains particularly influenced by Iran, and consults with it on most matters.^[241] As of 2018 Iran has become Iraq's top trading partner, with an annual turnover of approximately $12 billion USD compared to the $6 billion USD in trade between Iraq and Saudi Arabia. In addition to fostering economic ties, Tehran furthered its influence by aiding the Iraqi government in its fight against the push for independence in Iraqi Kurdistan.^[242] Saudi Arabia has responded by strengthening its ties to the Kurdistan Regional Government, seeing it as a barrier to the expansion of Iranian influence in the region, while also adopting a soft power approach to improve relations with the Iraqi government.^[243][244]

Izzat Ibrahim al-Douri, former Ba'athist official and leader of the Naqshbandi Army insurgent group, has repeatedly praised Saudi efforts to constrain Iranian clout in Iraq.^[245][246]

Recently, Saudi Arabia has developed a close relationship with Shia cleric Muqtada al-Sadr, the leader of the Sadrist Movement and the Peace Companies militia.^[247]

Saudi Arabia and Iran have sought to extend their influence in Bahrain for decades. While the majority of Muslims in Bahrain are Shia, the country is ruled by the Sunni Al Khalifa family. Iran claimed sovereignty over Bahrain until 1970, when Shah Mohammad Reza Pahlavi abandoned claims after negotiations with the United Kingdom.^[248] The Iranian Revolution led to resumed interest in Bahraini affairs. In 1981, the front organization Islamic Front for the Liberation of Bahrain led a failed coup attempt to install a Shia theocratic regime led by Hadi al-Modarresi. Since then, the government has accused Iran of supporting terrorist plots within its borders.^[249]

Sunni states have long feared that Iran might stir up unrest among regional Shia minority populations, especially in Bahrain. The Al Khalifa regime's stability depends heavily on Saudi support. The island is connected to Saudi Arabia by the 25 kilometer King Fahd Causeway, and its proximity to Saudi Arabia's oil-rich, majority Shia Eastern Province is viewed by Riyadh as a security concern. Any political gains by the Shia in Bahrain are seen by the Saudis as gains for Iran.^[250]

In response to the Arab Spring in 2011, the GCC regimes sought to maintain their legitimacy through social reform, economic handouts, and violent repression. Member states also distributed a share of their combined oil wealth to Bahrain and Oman to maintain stability.^[251] Saudi-led GCC forces quickly intervened in support of the Al Khalifa regime to put down the anti-government uprising in Bahrain.

The Bahraini government publicly blamed Iran for the protests, but an independent commission established by King Hamad rejected the claim, instead highlighting human rights abuses committed in the crackdown.^[252][66] The protests, along with the Iran nuclear deal, strained Bahrain's relationship with the United States. Bahrain has sought closer ties with Russia as a result, but this has been limited due to Saudi Arabia's alliance with the US.^[253]

Following the onset of the Arab Winter, Bahrain accused Iran of orchestrating several domestic incidents as part of a campaign to destabilize the country. Tehran denied all allegations and accused the government of Bahrain of blaming its own internal problems on Iran after every incident.^[168] In August 2015, authorities in Bahrain arrested five suspects over a bombing in Sitra. Officials linked the attacks to the Revolutionary Guard and Hezbollah, although Iran denied any involvement.^[254] In January 2016, Bahrain joined Saudi Arabia in cutting diplomatic ties with Tehran following the attacks on Saudi diplomatic missions in Iran.^[255] In November 2017, Bahrain called an explosion on its main oil pipeline "terrorist sabotage" linked to Iran, drawing a rebuke from Tehran. Saudi Arabia also referred to the incident as an "attack on the pipeline".^[168]

In 2008, Saudi Arabia proposed creating an Arab force backed by US and NATO air and sea power to intervene in Lebanon and destroy Iranian-backed Hezbollah, according to a US diplomatic cable released by WikiLeaks. According to the cable Saudi argued that a Hezbollah victory against the Siniora government "combined with Iranian actions in Iraq and on the Palestinian front would be a disaster for the US and the entire region".^[256][257]

In February 2016 Saudi Arabia banned their citizens from visiting Lebanon and suspended military aid due to possible Iranian influence and Lebanon's refusal to condemn the attack on Saudi embassy.^[258][259] Furthermore, Bahrain, Kuwait, and the United Arab Emirates advised all their citizens not to travel to Lebanon and urged them to leave immediately.^[260]

Lebanese Prime Minister Saad Hariri resigned on 4 November 2017. The situation was seen as a power play by Saudi Arabia to increase its influence in Lebanon and counterbalance Iran's victories in Iraq and Syria.^[261][262] In a televised speech from Saudi Arabia, Hariri criticized Hezbollah and blamed Iran for causing "disorder and destruction" in Lebanon. Hezbollah leader Hassan Nasrallah responded by accusing Hariri of resigning on Riyadh's orders.^[263]

The rivalry has contributed to the ongoing instability in Afghanistan. Afghanistan shares historical ties with Iran, and is strategically important to Saudi Arabia. After the Cold War, Saudi policy shifted from fighting the spread of communism to containing Iranian influence in South and Central Asia.^[84]

Saudi Arabia was one of three countries to officially recognize the Sunni Taliban government in 1996, along with its allies Pakistan and the United Arab Emirates. During the Afghan Civil War, Iran and Saudi Arabia supported opposing militant factions. Iran assisted the Shia Hizb-i-Wahdat, while Saudi Arabia provided financial support to the Wahhabist Ittihad-i Islami.^[264]

In 2001, the invasion of Afghanistan and the removal of the Taliban in the wake of the September 11 attacks benefited Iran, which had previously been on the brink of war with the group. The regime change removed Iran's primary threat along its eastern borders, and the removal of Saddam Hussein two years later further bolstered its position, allowing it to refocus its efforts on other areas, especially Syria and Yemen.^[265] In the ensuing years, Iran sought to expand its influence over Afghanistan. It provided limited support to the Taliban as a potential means of increasing leverage with the Afghan central government and creating a deterrent to conflict with the United States, although the support waned amid growing backlash in Afghanistan against perceived Iranian interference.^[266] Iran has also sought to expand soft influence by building pro-Iranian schools, mosques, and media centers, and by maintaining close ties with Afghanistan's Tajik and Hazara populations.^[266]

Since 1989 Pakistan has been dealing with sectarian conflict. The population is predominantly Sunni and has about 10-15% of Shia adherents.^[267]

Pakistan is economically dependent on Saudi Arabia and a key strategic ally. The country's economic stability relies heavily on foreign workers who send money home. The largest amount comes from the 1.5 million Pakistanis working in Saudi Arabia who sent home about $5.5 billion USD in remittances in 2017.^[268] Saudi Arabia has invested in the country's nuclear weapons projects, and believes it could use Pakistan to quickly obtain nuclear weapons at will.^[269] Riyadh also sees the province of Balochistan as a potential means of stirring ethnic unrest in neighboring Iran.^[270]

In 2015, Pakistan declared its neutrality in the conflict in Yemen after Saudi solicitations for military support. It ultimately provided some degree of covert support, joining Somalia in sending proxy forces to aid the Saudi-led campaign against Houthi rebels.^[36] In 2016, Saudi Arabia sought closer ties with Pakistan as part of its "look east" policy of expanding its reach to East and South Asia.^[271]

In February 2018, Saudi Arabia, acting on behalf of the GCC, joined China and Turkey in opposing a US-led initiative to place Pakistan on an international terror-financing watch list through the Financial Action Task Force. This move came days after Pakistan pledged to send 1,000 troops to the Gulf kingdoms for what it described as an advisory mission.^[268]

Iran has been accused of influencing young Pakistani Shias to act as proxies to further Iranian interests in Pakistan. The Iranian government has been suspected of militarizing Shia loyalists amongst Pakistan's local population and promoting sectarian sentiments to further achieve its goals.^[272] Many Pakistani Shias have also been suspected of traveling to parts of the Middle East including Syria and Lebanon to fight on behalf of the Iranian government.^{[273][274][275]}

Although both Iran and Saudi Arabia signed the Treaty on the Non-Proliferation of Nuclear Weapons in 1970 and 1988 respectively, a potential nuclear arms race has been a concern for years. Both governments claim that their programs are for peaceful purposes, but foreign governments and organizations have accused both of taking steps to obtain nuclear weapons capabilities.

Iran's ongoing nuclear program began in the 1950s under the Shah in cooperation with the United States as part of the Atoms for Peace program. The cooperation continued until the Iranian Revolution in 1979.^[276] Sanctions have been in place since then, and were expanded in 2006 with the passage of United Nation Security Council Resolution 1737 and Resolution 1696 in response to Iran's uranium enrichment program.

Saudi Arabia has considered several options in response to the Iranian program: acquiring its own nuclear capability as a deterrent, entering into an alliance with an existing nuclear power, or pursuing a regional nuclear-weapon-free zone agreement.^[277] It is believed that Saudi Arabia has been a major financier of Pakistan's integrated nuclear program since 1974, a project begun under former Prime Minister Zulfikar Ali Bhutto. In 2003 it was reported that Saudi Arabia had taken the "strategic decision" to acquire "off-the-shelf" atomic weapons from Pakistan, according to senior American officials.^[278] In 2003, The Washington Times reported that Pakistan and Saudi Arabia had entered a secret agreement on nuclear cooperation to provide the Saudis with nuclear weapons technology in return for access to cheap oil for Pakistan.^[279]

Following several years of negotiations for a nuclear deal framework between Iran and the P5+1 countries, the Joint Comprehensive Plan of Action (JCPOA) was signed in 2015. The deal raised concerns for Saudi Arabia, which saw it as a step toward reducing Iran's international isolation and potentially exacerbating the proxy conflict.^[280] However, Riyadh did not publicly denounce the deal at the time as Israel did.^[281] In 2018, Crown Prince Mohammad bin Salman stated that Saudi Arabia would move to obtain nuclear weapons if Iran's program is successful.^[282] He led a delegation to the United States to meet with Trump administration officials to discuss mutual concerns, including a potential US withdrawal from the Iran nuclear agreement.^[177] In April 2018, Israeli Prime Minister Benjamin Netanyahu gave a televised speech accusing Iran of covertly continuing the AMAD Project in violation of the JCPOA.^[283]

President Trump announced on 8 May 2018 that the United States would unilaterally withdraw from the JCPOA and reinstate previous sanctions against Iran in addition to imposing new sanctions.^[179] In anticipation of the decision, Iranian President Rouhani stated that Iran would remain in the deal if the remaining parties did the same, but was otherwise vague on how the country would respond to the US decision.^[284]