1953 Iran Coup Explained: Operation Ajax, Mossadegh Overthrow and CIA Role

Quick Answer:

The 1953 Iran coup, codenamed Operation Ajax by the CIA and Operation Boot by British intelligence, removed Iran's elected Prime Minister Mohammad Mossadegh from power in August 1953. It followed Iran's nationalization of the British-controlled Anglo-Iranian Oil Company and Cold War fears of Soviet influence. The coup strengthened Shah Mohammad Reza Pahlavi's rule and later fueled the anti-American sentiment behind the 1979 Iranian Revolution.

1953 Iran Coup Explained in Simple Words

The 1953 Iran Coup, often described as the Iran coup of 1953, was one of the most important events in modern Middle Eastern history. It changed Iran’s politics, damaged trust between Iran and the West, strengthened the rule of the Shah, and later became one of the major reasons behind anti-American feeling in Iran. This is why the coup is one of the starting points for understanding the wider US-Iran conflict history.

In simple words, the coup removed Iran’s Prime Minister Mohammad Mossadegh from power and strengthened the rule of Shah Mohammad Reza Pahlavi. The operation was supported by the United States and the United Kingdom. It was connected to oil, British economic interests, Cold War fears, and the struggle over who should control Iran’s future.

The coup is also known by its CIA codename: Operation Ajax. Britain’s MI6 used a separate codename for the same operation: Operation Boot.

To understand the 1953 Iran Coup properly, without reducing it to only one oil story, we need to look at Iran before the coup, the oil nationalization crisis, the role of Mossadegh, the involvement of the CIA and Britain, and the consequences that followed.

What Was the 1953 Iran Coup?

The 1953 Iran Coup was the overthrow of Iran’s Prime Minister Mohammad Mossadegh in August 1953. Mossadegh was removed from power after a political crisis involving Iran’s oil industry, the British government, the United States, the Shah of Iran, and anti-Mossadegh forces inside Iran.

Before the coup, Iran had a constitutional monarchy. This means Iran had a king, known as the Shah, but there was also a parliament and a prime minister. The Shah was Mohammad Reza Pahlavi, and the prime minister was Mohammad Mossadegh. In this system, Prime Minister Mohammad Mossadegh led the government while the Shah remained the monarch.

Mossadegh became popular because he wanted Iran to control its own oil. At that time, Iranian oil industry was heavily controlled by the British-owned Anglo-Iranian Oil Company. Mossadegh believed that Iran’s oil wealth should benefit the Iranian people, not mainly foreign powers.

In 1951, Iran nationalized its oil industry. This means Iran took control of the oil industry from the British company. Britain strongly opposed this decision. This decision became the center of the Iran oil nationalization crisis. The dispute became bigger and bigger, and eventually the United States also became involved.

In August 1953, a covert operation helped remove Mossadegh from power. After the coup, the Shah’s authority became much stronger. Mossadegh was arrested, tried, and later kept under house arrest. The Shah continued to rule Iran for more than two decades, until the Iranian Revolution of 1979. Declassified CIA records confirming the agency’s role are now publicly available through the National Security Archive.”

So, in short, the 1953 Iran Coup was not just a change of government. It became a turning point in Iran’s modern history.

Who Was Mohammad Mossadegh, the Iranian Prime Minister?

Mohammad Mossadegh was one of the most important political leaders in modern Iranian history. He was Iran’s prime minister from 1951 to 1953. He was known for nationalism, constitutional politics, and his fight to bring Iran’s oil under Iranian control.

Mossadegh was not a communist and he was not trying to turn Iran into a Soviet-style country. He was a nationalist leader. His main goal was to reduce foreign control over Iran and make the Iranian government more independent.

Mossadegh came to power in April 1951, during a political crisis that followed the assassination of the previous prime minister. Iran’s parliament, the Majlis, nominated him amid growing public support for the oil nationalization movement he led. The Shah, whose constitutional role included appointing the prime minister chosen by parliament, then formally appointed him. In other words, Mossadegh reached office through Iran’s existing parliamentary process — not through a coup or a revolution of his own.

One of the biggest reasons Mossadegh became famous was his decision to nationalize Iran’s oil industry. For many Iranians, this was a symbol of dignity and independence. They felt that Iran’s natural resources had been controlled by foreigners for too long.

Mossadegh also wanted to limit the power of the Shah and strengthen the authority of elected institutions. This created tension between Mossadegh and the monarchy. Supporters of Mossadegh saw him as a defender of Iranian democracy and independence. His opponents saw him as dangerous, unstable, or too weak to control the political crisis.

A common question people ask is: Was Mohammad Mossadegh democratically elected?

The answer needs to be explained carefully. Mossadegh was not elected directly by the people like a modern president. Iran had a parliamentary system. He became prime minister through Iran’s constitutional and parliamentary process. He had strong public support and was seen by many Iranians as a legitimate national leader.

This is why many historians describe the coup as the removal of a democratic or constitutional leader. The key point is that Mossadegh was not simply a dictator removed by foreign powers. He was Iran’s prime minister, and his removal changed Iran’s political direction.

Oil Nationalization and the Anglo-Iranian Oil Company Crisis

To understand the 1953 coup, we must first understand the Iran oil nationalization crisis.

Iran had huge oil resources, but for many years, the British-controlled Anglo-Iranian Oil Company had major control over Iran’s oil industry. This company later became connected to what is known today as BP.

Many Iranians believed the oil arrangement was unfair. They felt Britain was making huge profits while Iran was not getting a fair share of its own natural wealth. Oil was not just an economic issue. It became a question of national pride, independence, and sovereignty. Oil has remained central to Middle East geopolitics, especially in chokepoints like the Strait of Hormuz. In 1951, Mossadegh and his supporters nationalized Iran’s oil industry. This meant Iran took control of the oil industry from the Anglo-Iranian Oil Company. For Iranians who supported Mossadegh, this was a historic victory. It showed that Iran would no longer accept foreign control over its most valuable resource.

Britain reacted strongly. The British government opposed the nationalization and tried to pressure Iran economically and diplomatically. Britain imposed an oil embargo and tried to isolate Iran — a standoff historians often call the Abadan Crisis, named after Iran’s main oil refinery. This badly affected Iran’s economy.

The oil crisis created a serious problem. Iran had oil, but selling it became difficult because Britain used its influence to block Iranian oil exports. The Iranian economy suffered. Political tension inside Iran increased. Mossadegh’s enemies used the economic crisis to attack his leadership.

At first, the United States was not fully ready to support a coup. But as the Cold War became more intense, American officials became increasingly worried about instability in Iran. They feared that chaos in Iran could help the Soviet Union or the Iranian communist Tudeh Party gain influence.

So, oil was not the only reason for the coup, but it was one of the main causes. The oil nationalization crisis created the conflict that brought Britain, the United States, Mossadegh, and the Shah into direct confrontation.

Why was Mohammad Mossadegh overthrown in 1953?

Mohammad Mossadegh was overthrown because of a combination of reasons: oil politics, British pressure, Cold War fears, and concern that Iran might become unstable or move closer to the Soviet Union. It is too simple to say the coup happened only because of oil — the situation was bigger than that, and several forces pushed toward the same outcome around the same time.

British Oil Interests

Britain had strong economic interests in Iranian oil, and the nationalization of the Anglo-Iranian Oil Company was a major blow to British power. Britain wanted Mossadegh removed because he challenged British control over Iranian oil. But Britain also needed American support to act. After World War II, Britain was weaker than before, while the United States had become the leading Western power, so British officials worked to convince Washington that Mossadegh was a shared strategic problem, not only a British commercial one.

Cold War Fears and Soviet Influence

The Cold War changed American thinking. The United States was worried about the spread of Soviet influence around the world, and Iran mattered because it bordered the Soviet Union and had major oil resources. American officials feared that if Iran became unstable, the Soviet Union or the Iranian communist Tudeh Party might benefit.

Mossadegh, the Shah and Internal Iranian Politics

Mossadegh’s relationship with the Shah and other political forces became increasingly tense, and Iran’s internal politics were unstable. The economy was under pressure because of the oil crisis, and Mossadegh’s opponents inside Iran — royalists, some military officers, and conservative political and religious figures — used that instability to turn against him. The United States and Britain believed removing Mossadegh would protect Western interests and stabilize Iran under the Shah.

So, the main reasons were:

Britain wanted to protect its oil interests.
The United States feared Soviet influence during the Cold War.
Western powers saw Mossadegh as difficult to control.
The Shah and anti-Mossadegh forces inside Iran wanted to regain power.
The oil crisis had created political and economic instability.

From the Western point of view at the time, the coup looked like a way to prevent chaos and protect strategic interests. But from the Iranian nationalist point of view, it looked like foreign interference against Iran’s independence.

This difference in perspective is one reason the coup still matters today.

What Was Operation Ajax?

Operation Ajax was the codename for the covert operation that helped remove Mohammad Mossadegh from power in 1953.

It was planned and supported by the CIA, working with Britain’s intelligence service, MI6, which used its own codename for the same operation — Operation Boot.

The goal of Operation Ajax was to weaken Mossadegh, remove him from office, and strengthen the position of the Shah. The operation involved propaganda, political pressure, street demonstrations, support for anti-Mossadegh forces, and coordination with military and political figures inside Iran.

The operation did not happen in one simple step. It was messy and risky.

The plan involved getting the Shah to dismiss Mossadegh and appoint General Fazlollah Zahedi as the new prime minister. However, the first attempt did not succeed as planned. Mossadegh resisted, and the Shah temporarily fled Iran.

For a moment, it looked like the operation had failed.

But then events changed quickly. Anti-Mossadegh crowds, military units, royalist forces, and political networks helped turn the situation against Mossadegh. On August 19, 1953, Mossadegh’s government collapsed. Zahedi became prime minister, and the Shah returned to Iran with greater power.

A common question is: Was Operation Ajax successful?

In the short term, yes. It achieved its immediate goal: Mossadegh was removed, Zahedi became prime minister, and the Shah’s rule was strengthened.

But in the long term, the success is much more questionable. The coup created deep resentment in Iran. Many Iranians saw it as proof that the United States and Britain were willing to interfere in Iran’s politics to protect their own interests. This anger later became part of the wider anti-Shah and anti-American mood that grew before the 1979 Iranian Revolution.

So Operation Ajax was successful as a covert operation, but its long-term legacy was extremely damaging.

1953 Iran Coup Timeline

The 1953 Iran Coup becomes easier to understand when we see it as a timeline.

1951: Mossadegh becomes Prime Minister
Mohammad Mossadegh becomes prime minister of Iran. He soon supports the nationalization of Iran’s oil industry.

1951: Iran nationalizes its oil
Iran takes control of the oil industry from the British-controlled Anglo-Iranian Oil Company. This creates a major conflict with Britain.

1951–1953: Britain pressures Iran
Britain opposes oil nationalization and puts pressure on Iran through economic and diplomatic methods. Iran’s economy suffers.

1952–1953: Political crisis grows
Mossadegh faces growing opposition from the Shah, conservative forces, religious figures, military officers, and foreign governments.

1953: Operation Ajax is planned
The CIA and British intelligence support a plan to remove Mossadegh and strengthen the Shah.

August 15, 1953: First attempt fails
The first attempt to remove Mossadegh does not succeed. Mossadegh resists the move, and the Shah leaves the country.

August 19, 1953: Coup succeeds
Anti-Mossadegh forces, street crowds, and military units help overthrow Mossadegh’s government. General Fazlollah Zahedi becomes prime minister. Estimates suggest that between 200 and 300 people were killed in the clashes and unrest in Tehran during the coup.

After the coup: Shah returns
The Shah returns to Iran with stronger authority. Mossadegh is arrested and later placed under house arrest.

1953–1979: Shah’s rule becomes stronger
The Shah rules Iran with strong Western support until he is overthrown in the Iranian Revolution of 1979.

This timeline shows that the coup was not one isolated event. It was the result of years of conflict over oil, power, foreign influence, and Iran’s political future.

CIA and US Involvement in the 1953 Iran Coup

The CIA played a major role in Operation Ajax. The United States supported the operation because American officials believed Mossadegh’s government could lead to instability and possible Soviet influence in Iran.

One important figure connected with Operation Ajax was Kermit Roosevelt Jr., a CIA officer involved in the operation against Mossadegh. His role is often mentioned in discussions of the 1953 Iran Coup because Operation Ajax was not an ordinary diplomatic pressure campaign. It was a covert political operation that used propaganda, local networks, royalist support, and anti-Mossadegh forces inside Iran to shift power away from Mossadegh and toward the Shah.

The CIA’s involvement included political planning, propaganda, support for anti-Mossadegh networks, and coordination with Iranian figures who opposed Mossadegh. The operation was not simply an open military invasion. It was a covert political operation.

One reason the CIA became involved was the Cold War. During the early 1950s, the United States was trying to stop the spread of communism. Iran’s location made it very important. It bordered the Soviet Union and had major oil resources. If Iran fell into Soviet influence, the United States believed it would be a major strategic defeat.

Another reason was British pressure. Britain had lost control over Iranian oil after nationalization and wanted American help. The United States became more willing to support action after President Dwight Eisenhower took office.

A common question is: Did the CIA admit it was behind Iran’s coup?

Over time, more documents and official statements have confirmed the CIA’s role in the coup, including a 2013 acknowledgment reported by the Guardian confirming the agency’s involvement. The event is now widely understood as a CIA-backed operation supported by the United States and Britain.

However, it is important to explain this carefully. The CIA did not act alone in a vacuum. The coup also involved Iranian actors: royalists, military officers, politicians, religious networks, and anti-Mossadegh groups inside Iran. Without internal Iranian opposition to Mossadegh, the operation would have been much harder.

Still, the foreign role was extremely important. For many Iranians, this became the main lesson of 1953: foreign powers could interfere in Iran’s political system when their interests were threatened.

That memory shaped Iran’s later attitude toward the United States.

British Role in the 1953 Iran Coup

Britain had a major role in the events that led to the 1953 Iran Coup, as detailed in Britannica’s account of the crisis. The British government was deeply connected to the Anglo-Iranian Oil Company and wanted to protect British oil interests in Iran.

Before nationalization, Britain benefited greatly from Iranian oil. The Anglo-Iranian Oil Company was one of Britain’s most valuable overseas assets. When Mossadegh nationalized Iran’s oil, Britain saw it as a direct threat.

Britain tried to pressure Iran through legal, diplomatic, and economic methods. It supported an oil embargo and tried to prevent Iran from selling oil internationally. But these actions did not force Mossadegh to reverse nationalization.

Because Britain had less power after World War II, it needed the United States. British officials worked to convince American leaders that Mossadegh was not just a problem for Britain, but also a danger to Western interests during the Cold War.

This is where oil and Cold War politics came together.

A common question is: Was Iran ruled by the British?

No, Iran was not formally a British colony like India had been. But Britain had strong economic and political influence in Iran, especially through oil. That influence made many Iranians feel that their country was not fully independent.

So Britain’s role in the coup was mainly connected to oil, influence, and the desire to remove a leader who challenged British power.

Shah of Iran and the 1953 Coup

The Shah of Iran in 1953 was Mohammad Reza Pahlavi. He had become Shah in 1941 after his father, Reza Shah, was forced to abdicate during World War II.

Before the coup, the Shah was important, but his power was limited by Iran’s constitutional system and by the popularity of Mossadegh. Mossadegh wanted the Shah to remain a constitutional monarch, not an all-powerful ruler.

This created tension.

During Operation Ajax, the Shah played a symbolic and legal role. The plan involved the Shah dismissing Mossadegh and appointing General Fazlollah Zahedi as prime minister. But the Shah was nervous and uncertain. When the first attempt failed, he fled Iran.

After the coup succeeded, the Shah returned. His position became much stronger. Over the next years, he became increasingly powerful and ruled Iran with strong support from the United States.

For supporters of the Shah, he represented modernization, stability, and a pro-Western direction. Under his rule, Iran experienced development, reforms, and closer ties with the West.

But for his opponents, the Shah represented dictatorship, repression, and foreign-backed rule. His government became associated with secret police, political control, and lack of democratic freedom.

The 1953 coup therefore transformed the Shah’s position. Before the coup, he was a monarch struggling with an elected prime minister. After the coup, he became the central ruler of Iran.

What Happened to Mohammad Mossadegh After the Coup?

After the 1953 coup, Mohammad Mossadegh was arrested. He was put on trial and accused of acting against the monarchy. He was convicted and sentenced to prison.

After serving time in prison, Mossadegh was placed under house arrest. He spent the rest of his life under restrictions and died in 1967.

His political movement was weakened, and many of his supporters were arrested, silenced, or pushed out of power. The National Front, which had supported Mossadegh’s nationalist politics, lost influence after the coup.

But Mossadegh did not disappear from Iranian memory. In fact, over time, he became a symbol of Iranian nationalism and resistance to foreign interference. For many Iranians, Mossadegh represented a lost chance for a more independent and democratic Iran.

This is why the question “What happened to Mohammad Mossadegh?” matters so much. His personal fate became part of a bigger story: the defeat of a nationalist political movement and the rise of a stronger monarchy under the Shah.

Effects and Consequences of the 1953 Iran Coup

The 1953 Iran Coup had both short-term and long-term consequences.

In the short term, Mossadegh was removed from power. General Fazlollah Zahedi became prime minister. The Shah returned to Iran and became much stronger. The oil crisis was eventually settled in 1954, when a new international consortium of Western oil companies — including British, American, Dutch, and French firms — took over Iran’s oil production, replacing the arrangement Mossadegh had nationalized.

For the United States and Britain, the coup looked like a successful operation. A difficult nationalist leader had been removed, Iran remained in the Western camp during the Cold War, and the Shah became a strong ally.

But the long-term consequences were much more serious.

First, the coup weakened democratic politics in Iran. Instead of allowing Iran’s political system to develop through internal struggle, foreign-backed intervention changed the direction of the country.

Second, it strengthened the Shah’s authoritarian rule. Over time, the Shah became more powerful, and political opposition became more restricted.

Third, it created deep distrust toward the United States and Britain. Many Iranians came to believe that Western countries cared more about oil and influence than Iran’s independence.

Fourth, it became part of the emotional and political background to the 1979 Iranian Revolution. The coup was not the only cause of the revolution, but it helped create the belief that the Shah’s rule was connected to foreign interference.

Fifth, the coup damaged America’s image in Iran. Even decades later, Iranian leaders and political movements used the 1953 coup as an example of why the United States could not be trusted — a dynamic explored in depth by the Washington Post.

So the biggest consequence of the coup was not only the removal of Mossadegh. The bigger consequence was the long-term destruction of trust between Iran and the West. That broken trust later shaped the modern US-Iran conflict, from the 1979 revolution to sanctions and nuclear tensions.

How the 1953 Coup Shaped US-Iran Relations

The 1953 Iran Coup shaped US-Iran relations for decades.

After the coup, the United States became closely connected to the Shah. Iran became one of America’s important allies in the Middle East. The Shah bought American weapons, supported Western interests, and helped contain Soviet influence.

For some time, this relationship seemed successful from the American point of view. Iran looked stable, anti-communist, and pro-Western.

But inside Iran, many people saw things differently. They saw the Shah as a ruler whose power had been strengthened by foreign intervention. They saw the United States as a country that had helped remove a popular nationalist leader. This created resentment.

When the Iranian Revolution happened in 1979, led by Ayatollah Khomeini, anti-American feeling became one of its major features. Revolutionaries remembered the 1953 coup as proof that the United States had interfered in Iran before and might interfere again.

This is one reason the 1979 hostage crisis happened in such an emotional atmosphere. Many Iranians did not see the United States only as a foreign country. They saw it as a power that had shaped Iran’s modern history.

The 1953 coup did not create all problems between the United States and Iran, but it became one of the deepest wounds in the relationship.

Even today, when people discuss US-Iran tensions, the coup is often mentioned. It helps explain why Iran’s leaders talk so much about foreign interference and why many Iranians have a complicated view of American power.

To understand how this event connects to modern tensions, read our complete guide on the US-Iran conflict.

This history resurfaced again during the 2025 Israel-Iran conflict, when commentators and Iranian officials invoked the 1953 coup to frame renewed U.S. and Israeli pressure on Tehran as a continuation of the same pattern of foreign interference.

FAQs About the 1953 Iran Coup

When did the 1953 Iran Coup happen?

The coup took place in August 1953. The most important day was August 19, 1953, when Mossadegh’s government was overthrown and anti-Mossadegh forces took control.

What was Operation Ajax?

Operation Ajax was the CIA-backed covert operation, supported by British intelligence, that helped remove Prime Minister Mohammad Mossadegh from power and strengthen the Shah of Iran.

Who did Operation Ajax overthrow?

Operation Ajax helped overthrow Mohammad Mossadegh, the prime minister of Iran. It did not overthrow the Shah. In fact, the coup strengthened the Shah’s power.

Who put the Shah back in power after the 1953 coup?

Mohammad Reza Pahlavi was already Iran’s monarch before 1953 — the CIA and MI6 did not install him as Shah. What Operation Ajax did was help remove Mossadegh and restore the Shah’s political authority, with support from Iranian royalist officers, military units, and street networks working alongside the American and British operation.

Was Operation Ajax successful?

In the short term, yes. It removed Mossadegh and strengthened the Shah. But in the long term, it created deep resentment in Iran and damaged US-Iran relations.

What was the main reason for the 1953 coup in Iran?

The main reasons were oil politics, British pressure, Cold War fears, and concern that Iran might become unstable or move closer to Soviet influence.

Was Mossadegh democratically elected?

Mossadegh became prime minister through Iran’s constitutional and parliamentary system. He was not directly elected like a modern president, but he had strong public support and was seen by many as a legitimate national leader.

What happened to Mossadegh after the coup?

Mossadegh was arrested, tried, imprisoned, and later kept under house arrest. He died in 1967.

Did the 1953 coup lead to the 1979 Iranian Revolution?

The 1953 coup was not the only cause of the 1979 Iranian Revolution. However, it helped create long-term anger against the Shah and distrust toward the United States. This made it an important background event in the story of the revolution.

Was Iran a democracy in 1953?

Iran was a constitutional monarchy with an elected parliament and a prime minister, not a full democracy in the modern sense. Mossadegh became prime minister through this parliamentary system and had strong public backing, which is why many historians describe his removal as the overthrow of a constitutional government rather than simply a dictator.

What was Operation Boot?

Operation Boot was the codename British intelligence (MI6) used for the same covert operation that the CIA called Operation Ajax — both aimed to remove Prime Minister Mohammad Mossadegh from power.

Consequences of the 1953 Iran Coup: Short-Term vs. Long-Term

Area	Short term (1953–1960s)	Long term (1970s–present)
Political power	Shah's authority strengthened; Mossadegh imprisoned	Shah's rule became increasingly authoritarian until 1979
Oil industry	1954: new Western-controlled oil consortium formed	Set a precedent for resource-control disputes worldwide
US-Iran relations	Iran became a close Cold War ally of the US	Deep distrust that shaped the 1979 hostage crisis and modern tensions
Iranian public opinion	Nationalist movement weakened	Coup became a symbol of foreign interference, invoked even in 2025–2026 tensions

Conclusion

The 1953 Iran Coup was a turning point in Iran’s modern history. It removed Mohammad Mossadegh, strengthened the Shah, protected Western strategic interests, and changed the future of US-Iran relations.

At the center of the story were oil, nationalism, Cold War fears, and foreign influence. Mossadegh wanted Iran to control its own oil and limit foreign power. Britain wanted to protect its oil interests. The United States feared instability and Soviet influence. The Shah wanted to preserve and strengthen his rule.

Operation Ajax achieved its short-term goal, but its long-term impact was deeply damaging. It weakened trust, strengthened authoritarian rule, and became a symbol of foreign interference in Iran.

That is why the 1953 Iran Coup is still important today. It is not only a historical event. It is one of the key memories that shaped how Iran views the United States, the West, and foreign involvement in its politics.