On 19 August 1953 a coup d'état overthrew the Prime Minister of Iran, Mohammad Mosaddegh, strengthening the rule of Mohammad Reza Pahlavi, the Shah of Iran. It was instigated by the United Kingdom (MI6), under the name Operation Boot and by the United States (CIA), under the name TP-AJAX Project or Operation Ajax. A key motive was to protect British oil-interests in Iran after Mosaddegh had nationalized the country's oil industry in 1951.
Mosaddegh had sought to audit the documents of the Anglo-Iranian Oil Company (AIOC), a British corporation (subsequently part of BP), to verify that AIOC was paying the contracted royalties to Iran, and to limit their control over Iranian oil reserves. Upon the AIOC's refusal to cooperate with the Iranian government, the Iranian parliament (the Majlis) voted to nationalize Iran's oil industry (March 1951) and to expel foreign corporate representatives from the country. After this vote, Britain instigated a worldwide boycott of Iranian oil to pressure Iran economically. Initially, Britain mobilized its military to seize control of the British-built Abadan oil refinery, then the world's largest, but the U.K. Prime Minister Clement Attlee opted instead to tighten the economic boycott while using agents to undermine Mosaddegh's government. Judging Mosaddegh to be unamenable and fearing the growing influence of the communist Tudeh, Attlee's successor as UK prime minister, Winston Churchill, decided in early 1953 to solicit the Eisenhower administration and to overthrow Iran's government. The preceding Truman administration had opposed a coup, fearing the precedent that Central Intelligence Agency involvement would set, and the U.S. government had been considering unilateral action (without UK support) to assist the Mosaddegh government as late as 1952. British intelligence and the UK government's solicitations to the US were instrumental in initiating and planning the coup. In the week before the coup, Mosaddegh consolidated power through a controversial referendum to dissolve parliament.
The events of the coup unfolded between 15 and 19 of August, after months of planning by the United States' CIA, and United Kingdom's MI6. On 15 August, an officer of the Imperial Guard of the Shah (Persian for 'king') was dispatched to Tehran to deliver the Shah's dismissal decree to Mosaddegh, a move that was legally questionable under the 1906–1907 Iranian Constitution. Mosaddegh's supporters arrested the officer on arrival, and the Shah, Mohammed Reza Pahlavi fled to Italy shortly afterward. After the Shah had left, a wave of protests organized by the CIA failed to overthrow Mosaddegh. Although the initial attempt failed, the CIA continued coordinating with royalist networks, clerical figures, and elements of the military. On 19 August, demonstrators and military units backed by the CIA gained control of key institutions in Tehran and seized the government, leading to Mosaddegh's overthrow on 19 August, allowing the Shah to return to Iran on 22 August.
Following the coup, General Fazlollah Zahedi, who had led the military units in support of the coup, formed a government which allowed the Shah of Iran to rule more firmly as monarch. After his return to Iran, the Shah relied heavily on United States support to retain power. According to the CIA's declassified documents and records, the CIA hired some of the most feared mobsters in Tehran to stage pro-shah riots on 19 August. Other men paid by the CIA were brought into Tehran in buses and trucks and took over the streets of the city. Between 200 and 300 people were killed because of the conflict. Mosaddegh was arrested, tried and convicted of treason by the Shah's military court. On 21 December 1953, he was sentenced to three years in jail; he remained under house arrest until he died in 1967. Mosaddegh supporters were imprisoned, and several received the death penalty. The coup strengthened the Shah's authority, and he continued to rule Iran for the next 26 years as an authoritarian, pro-Western monarch, until overthrown in the Iranian Revolution in 1979.
In August 2013, the U.S. government formally acknowledged the U.S. role in the coup by releasing a bulk of previously classified government documents that show it was in charge both of the planning and of the execution of the coup. According to American journalist Stephen Kinzer, the operation included false-flag attacks, paid protesters, provocations, the bribing of Iranian politicians and of high-ranking security and army officials, as well as pro-coup propaganda. The CIA is quoted as acknowledging that the coup took place "under CIA direction" and "as an act of U.S. foreign policy, conceived and approved at the highest levels of government". In 2023, the CIA took credit for the coup, this confirmed what many historians had already concluded previously, though because portions of the agency's records were destroyed, or remained classified for years, some historians had initially argued, on the basis of incomplete evidence, that Iranian domestic actors played the primary role in the coup, with the U.S. and Britain serving mainly in a supporting capacity.
On 19 August 1953 a coup d'état overthrew the Prime Minister of Iran, Mohammad Mosaddegh, strengthening the rule of Mohammad Reza Pahlavi, the Shah of Iran. It was instigated by the United Kingdom (MI6), under the name Operation Boot and by the United States (CIA), under the name TP-AJAX Project or Operation Ajax. A key motive was to protect British oil interests in Iran after Mosaddegh had nationalized the country's oil industry in 1951.
Mosaddegh had sought to audit the documents of the Anglo-Iranian Oil Company (AIOC), a British corporation (subsequently part of BP), to verify that AIOC was paying the contracted royalties to Iran, and to limit their control over Iranian oil reserves. Upon the AIOC's refusal to cooperate with the Iranian government, the Iranian parliament (the Majlis) voted to nationalize Iran's oil industry (March 1951) and to expel foreign corporate representatives from the country. After this vote, Britain instigated a worldwide boycott of Iranian oil to pressure Iran economically. Initially, Britain mobilized its military to seize control of the British-built Abadan oil refinery, then the world's largest, but the U.K. Prime Minister Clement Attlee opted instead to tighten the economic boycott while using agents to undermine Mosaddegh's government. Judging Mosaddegh to be unamenable and fearing the growing influence of the communist Tudeh, Attlee's successor as UK prime minister, Winston Churchill, decided in early 1953 to solicit the Eisenhower administration and to overthrow Iran's government. The preceding Truman administration had opposed a coup, fearing the precedent that Central Intelligence Agency involvement would set, and the U.S. government had been considering unilateral action (without UK support) to assist the Mosaddegh government as late as 1952. British intelligence and the UK government's solicitations to the US were instrumental in initiating and planning the coup. In the week before the coup, Mosaddegh consolidated power through a controversial referendum to dissolve parliament.
The events of the coup unfolded between 15 and 19 of August, after months of planning by the United States' CIA, and United Kingdom's MI6. On 15 August, an officer of the Imperial Guard of the Shah (Persian for 'king') was dispatched to Tehran to deliver the Shah's dismissal decree to Mosaddegh. Mosaddegh's supporters arrested the officer on arrival, and the Shah, Mohammed Reza Pahlavi fled to Italy shortly afterward. After the Shah had left, a wave of protests organized by the CIA failed to overthrow Mosaddegh. Although the initial attempt failed, the CIA continued coordinating with royalist networks, clerical figures, and elements of the military. On 19 August, demonstrators and military units backed by the CIA gained control of key institutions in Tehran and seized the government, leading to Mosaddegh's overthrow on 19 August, allowing the Shah to return to Iran on 22 August.
Following the coup, General Fazlollah Zahedi, who had led the military units in support of the coup, formed a government which allowed the Shah of Iran to rule more firmly as monarch. After his return to Iran, the Shah relied heavily on United States support to retain power. According to the CIA's declassified documents and records, the CIA hired some of the most feared mobsters in Tehran to stage pro-shah riots on 19 August. Other men paid by the CIA were brought into Tehran in buses and trucks and took over the streets of the city. Between 200 and 300 people were killed because of the conflict. Mosaddegh was arrested, tried and convicted of treason by the Shah's military court. On 21 December 1953, he was sentenced to three years in jail; he remained under house arrest until he died in 1967. Mosaddegh supporters were imprisoned, and several received the death penalty. The coup strengthened the Shah's authority, and he continued to rule Iran for the next 26 years as an authoritarian, pro-Western monarch, until overthrown in the Iranian Revolution in 1979.
In August 2013, the U.S. government formally acknowledged the U.S. role in the coup by releasing a bulk of previously classified government documents that show it was in charge both of the planning and of the execution of the coup. According to American journalist Stephen Kinzer, the operation included false-flag attacks, paid protesters, provocations, the bribing of Iranian politicians and of high-ranking security and army officials, as well as pro-coup propaganda. The CIA is quoted as acknowledging that the coup took place "under CIA direction" and "as an act of U.S. foreign policy, conceived and approved at the highest levels of government". In 2023, the CIA took credit for the coup, this confirmed what many historians had already concluded previously, though because portions of the agency's records were destroyed, or remained classified for years, some historians had initially argued, on the basis of incomplete evidence, that Iranian domestic actors played the primary role in the coup, with the U.S. and Britain serving mainly in a supporting capacity.
Background
Throughout the 19th century, Iran was caught between two competing powers, Russia and Britain. In 1892, the British diplomat George Curzon described Iran as "pieces on a chessboard upon which is being played out a game for the dominion of the world." During the latter half of the 19th century, the concession policies of the Qajar monarchy faced increasing opposition. In 1872, a representative of British entrepreneur Paul Reuter met with the Iranian monarch Naser al-Din Shah Qajar and agreed to fund the monarch's upcoming lavish visit to Europe in return for exclusive contracts for Iranian roads, telegraphs, mills, factories, extraction of resources, and other public works, in which Reuter would receive a stipulated sum for five years and 60% of all the net revenue for 20 years. However, the Reuter concession was never put into effect because of violent opposition at home and from Russia. In 1892, the monarch was forced to revoke a tobacco monopoly given to Major G. F. Talbot, following protests and a widespread tobacco boycott.
In 1901, Mozaffar ad-Din Shah Qajar granted a 60-year petroleum search concession to William Knox D'Arcy. D'Arcy paid £20,000 (equivalent to £2.8 million in 2024), according to journalist-turned-historian Stephen Kinzer, and promised equal ownership shares, with 16% of any future net profit, as calculated by the company. However, the historian L. P. Elwell-Sutton wrote, in 1955, that "Persia's share was 'hardly spectacular' and no money changed hands." On 31 July 1907, D'Arcy withdrew from his private holdings in Persia, and transferred them to the British-owned Burmah Oil Company. On 26 May 1908, British geologist George Bernard Reynolds struck oil at a depth of 1,180 feet (360 m). The company grew slowly until World War I, when Persia's strategic importance led the British government to buy a controlling share in the company, essentially nationalizing British oil production in Iran.
The British angered the Persians by intervening in their domestic affairs, including in the Persian Constitutional Revolution. widespread protests had forced Mozzafar al-Din Shah to allow for the Constitution of 1906, which limited his powers. It allowed for a parliament elected by the people to make the laws, and a prime minister to sign and carry them out. The prime minister would be confirmed by the shah after a vote in Parliament. Nevertheless, the new constitution gave the shah many executive powers as well. It allowed for the shah to issue royal decrees (Firman), gave him the power to dismiss prime ministers, appoint half of the members of the Senate (which was not convened until 1949), and introduce bills to dissolve Parliament. It abolished arbitrary rule, but the shah served as an executive, rather than in a ceremonial role. The Constitutional Revolution was opposed by the British and Russians, who attempted to subvert it through the backing of Mohammad Ali Shah Qajar (the son of Mozzafar-e-din Shah), who tried to break up the democratic government by force. A guerrilla movement led by Sattar Khan deposed him in 1910.
In the aftermath of World War I there was widespread political dissatisfaction with the royalty terms of the British petroleum concession, under the Anglo-Persian Oil Company (APOC), whereby Persia received 16% of "net profits". In 1921, after years of severe mismanagement under the Qajar dynasty, a coup d'état (allegedly backed by the British) brought a general, Reza Khan, into the government. By 1923, he had become prime minister, and gained a reputation as an effective politician with a lack of corruption. By 1925 under his influence, Parliament voted to remove Ahmad Shah Qajar from the throne, and Reza Khan was crowned Reza Shah Pahlavi, of the Pahlavi dynasty. Reza Shah began a rapid and successful modernization program in Persia, which up until that point had been considered to be among the most impoverished countries in the world. Nevertheless, Reza Shah was also a harsh ruler who did not tolerate dissent. By the 1930s, he had suppressed all opposition, and had sidelined the democratic aspects of the constitution. Opponents were jailed and in some cases even executed. While some agreed with his policies, arguing that it was necessary as Iran was in such turmoil, others argued that it was unjustified. One such opponent was a politician named Mohammad Mosaddegh, who was jailed in 1940. The experience gave him a lasting dislike for authoritarian rule and monarchy, and it helped make Mosaddegh a dedicated advocate of complete oil nationalization in Iran.
Reza Shah largely succeeded in attenuating the power of the colonial forces in Iran. However, he also needed them to help modernize the country. He did so by balancing the influence of various colonial powers, including that of Britain and Germany. In the 1930s, Reza Shah tried to terminate the APOC concession that the Qajar dynasty had granted, but Iran was still weak and Britain would not allow it. The concession was renegotiated on terms again favorable to the British (although the D'Arcy Concession was softened). On 21 March 1935, Reza Shah changed the name of the country from Persia to Iran. The Anglo-Persian Oil Company was then renamed the Anglo-Iranian Oil Company (AIOC).
After World War II had broken out, Reza Shah had declared Iran's neutrality, and attempted to appease the British, Soviets and Germans, all of whom maintained a degree of influence in Iran. In 1941, after the German invasion of the Soviet Union, British and Soviet forces invaded and occupied Iran, which was largely unopposed by the Iranian government and military. The primary reasons behind the Anglo-Soviet invasion was to remove German influence in Iran and secure control over Iran's oil fields and the Trans-Iranian Railway in order to deliver supplies to the USSR. Reza Shah was deposed and exiled by the British to South Africa, and his 22-year-old son Mohammad Reza Pahlavi was installed as the new Shah of Iran. Mohammad Reza Pahlavi was supported by the Allies because they viewed him as being less able to act against their interests in Iran. The new Shah, unlike his father, was initially a mild leader and at times indecisive. During the 1940s he did not for most part take an independent role in the government, and much of Reza Shah's authoritarian policies were rolled back. Iranian democracy effectively was restored during this period as a result.
The British occupation force withdrew from Iran after the end of the war. However, under Joseph Stalin, the Soviet Union's partly remained by sponsoring two People's Democratic Republics within Iran's borders. The related conflict was ended when the US lobbied for the Iranian Army to reassert control over the two occupied territories. The earlier agreed-upon Soviet–Iranian oil agreement would never be honored. Nationalist leaders in Iran became influential by looking for a reduction in long-term foreign interventions in their country—especially the oil concession which was profitable for the West and little profitable for Iran.
U.S. objectives in the Middle East remained the same between 1947 and 1952 but its strategy changed. Washington remained "publicly in solidarity and privately at odds" with Britain, its World War II ally. Britain's empire was steadily weakening, and with an eye on international crises, the U.S. re-appraised its interests and the risks of being identified with British colonial interests. "In Saudi Arabia, to Britain's extreme disapproval, Washington endorsed the arrangement between ARAMCO and Saudi Arabia in the 50/50 accord that had reverberations throughout the region."
Iran's oil had been discovered and later controlled by the British-owned AIOC. Popular discontent with the AIOC began in the late 1940s: a large segment of Iran's public and a number of politicians saw the company as exploitative and a central tool of continued British imperialism in Iran.
Oil nationalization crisis
Assassination attempt on the Shah; Mosaddegh becomes prime minister
In 1949, an assassin attempted to kill the Shah. Shocked by the experience and emboldened by public sympathy for his injury, the Shah began to take an increasingly active role in politics. He quickly organized the Iran Constituent Assembly to amend the constitution to increase his powers. He established the Senate of Iran, which had been a part of the Constitution of 1906 but had never been convened. The Shah had the right to appoint half the senators, and he chose men sympathetic to his aims. Mosaddegh thought this increase in the Shah's political power was not democratic; he believed that the Shah should "reign, but not rule" in a manner similar to Europe's constitutional monarchies. Led by Mosaddegh, political parties and opponents of the Shah's policies banded together to form a coalition known as the National Front. Oil nationalization was a major policy goal for the coalition.
By 1951, the National Front had won majority seats for the popularly elected Majlis (Parliament of Iran). According to Iran's constitution, the majority elected party in the parliament would choose its prime minister candidate by vote, after which the Shah would confirm the candidate to power. The Prime Minister Ali Razmara, who opposed the oil nationalization, was assassinated by the hardline Fadaiyan e-Islam (whose spiritual leader was the AyatollahAbol-Qassem Kashani, a mentor to the future AyatollahRuhollah Khomeini,). After the National Front dominated the voting in Parliament, Mosaddegh was confirmed prime Minister of Iran by the Shah (replacing Hossein Ala', who had replaced Razmara). Under heavy pressure by the National Front, the assassin of Razmara (Khalil Tahmasebi) was released and pardoned. For the time being, Mosaddegh and Kashani were allies of convenience, as Mosaddegh saw that Kashani could mobilize the "religious masses", while Kashani wanted Mosaddegh to drive out British and other foreign influence. Kashani's Fadaiyan mobs often violently attacked the opponents of nationalization and opponents of the National Front government, as well as "immoral objects", acting at times as unofficial "enforcers" for the movement. However, by late 1952 Mosaddegh was becoming increasingly opposed to Kashani, as the latter was contributing to mass political instability in Iran. Kashani in turn, berated Mosaddegh for not "Islamizing" Iran, as he (Mosaddegh) was a firm believer in the separation of religion and state.