How the US’s Operation Ajax changed Iran’s regime in 1953: CIA’s $5-million strategy and protests | Explained

1953 Iran coup explained: Operation Ajax, CIA strategy and street protests

Joint US-Israeli strikes on Saturday killed Iran’s Supreme Leader Ali Khamenei, dramatically escalating tensions in the region. Some reports suggest his son, Mojtaba Khamenei, could be considered as a successor, though no official announcement has been made.

However, this is not the first time the US has intervened to force political change in Iran. In 1953, the United States and the United Kingdom backed a coup that ousted Iran’s prime minister, Mohammad Mossadegh, after he moved to nationalise the country’s oil industry, ultimately reinstalling the Shah and shaping decades of Iranian politics.

1953 coup: Operation Ajax

Iran’s modern distrust of Western intervention traces back to 1953, when the United States and the United Kingdom supported the overthrow of then–prime minister Mohammad Mossadegh. Mossadegh had moved to nationalise Iran’s oil industry, challenging British and Western interests at the height of the Cold War.

The covert operation, known as Operation Ajax, helped restore the authority of Shah Mohammad Reza Pahlavi, who went on to rule with Western backing. Decades later, declassified CIA documents confirmed US involvement in the coup. In 2009, former US President Barack Obama publicly acknowledged Washington’s role.

What happened

Declassified documents cited by CNN showed that the CIA, working with Britain’s Secret Intelligence Service, helped organise protests against Iran’s prime minister Mohammad Mossadegh in 1953, a movement that was later backed by elements of the army. Within two days of General Fazlollah Zahedi assuming office, the CIA made $5,000,000 available to help stabilise the new administration.

Mossadegh had sought to nationalise Iran’s oil industry, a move that threatened British and US interests reliant on Middle Eastern crude. While the policy drew strong domestic support and was viewed by some as a strategic gain for the Soviet Union during the Cold War, it intensified tensions with Western powers.

The coup ultimately reinforced the rule of Shah Mohammad Reza Pahlavi, a close US ally. However, resentment over foreign interference deepened over time. By the late 1970s, widespread protests erupted across Iran, culminating in the 1979 Islamic Revolution that overthrew the monarchy and established the Islamic Republic under clerical leadership.

From monarchy to Islamic Republic

The Shah’s rule saw rapid modernisation but also growing repression, widening inequality, and anger over close ties with Washington. By the late 1970s, mass protests swept the country. The 1979 Islamic Revolution ousted the monarchy and brought Ruhollah Khomeini to power, establishing the Islamic Republic under the doctrine of Velayat-e Faqih. After Khomeini died in 1989, Ali Khamenei assumed the role of Supreme Leader.

Conflict since 2025

Tensions between Iran, Israel and the United States erupted into open warfare in June 2025, when Israel launched strikes on Iranian nuclear and military facilities, triggering large-scale retaliation. A 12-day conflict ended with a ceasefire mediated by Washington and Doha on June 24, 2025.

After months of fragile calm, a renewed US-Israel military campaign began on February 28, 2026, targeting Iranian leadership, missile systems and nuclear infrastructure. The operation resulted in the death of Khamenei and senior officials, prompting Iranian counter-strikes on US bases and Israeli territory.

Israel’s objectives and symbolism

The Israeli operation, dubbed “Operation Rising Lion”, carries symbolic weight. The lion-and-sun emblem was a historic Persian motif and featured on Iran’s flag during the Pahlavi era before 1979.

As military operations intensify, the prospect of regime change once again looms over Iran, reviving historical memories of foreign intervention and reshaping the geopolitical landscape of the Middle East.