Overview
Operation Boot (British codename) — known in the United States as Operation TPAJAX — was a joint MI6 and CIA covert operation that overthrew the democratically elected Iranian Prime Minister Mohammad Mosaddegh on 19 August 1953. The operation restored the absolute power of Shah Mohammad Reza Pahlavi and secured Western control over Iranian oil production, ending a nationalisation crisis that had threatened Anglo-Iranian Oil Company (now BP) revenues.
The coup is one of the most thoroughly documented regime-change operations in intelligence history. The CIA formally acknowledged its role in a 2013 document release through the National Security Archive, stating: “The military coup that overthrew Mosaddegh and his National Front cabinet was carried out under CIA direction as an act of US foreign policy.”
Background: The Oil Nationalisation Crisis
In 1951, Mosaddegh’s National Front government nationalised the Anglo-Iranian Oil Company, which had operated Iranian oil fields under terms widely seen as exploitative — Iran received a 16% royalty while Britain retained the majority of profits. The British government imposed a naval blockade and international boycott. When diplomatic pressure failed, MI6 approached the CIA with a proposal for covert regime change. The Truman administration initially declined. The Eisenhower administration, which took office in January 1953 and framed the crisis in Cold War terms, agreed.
Operational Mechanics
MI6 officer Norman Darbyshire ran the British side from Cyprus. CIA officer Kermit Roosevelt Jr. (grandson of Theodore Roosevelt) ran the American side from inside Tehran. The operation involved: bribing Iranian newspaper editors to run anti-Mosaddegh propaganda, paying street gangs and military officers to organise pro-Shah demonstrations, and staging false-flag attacks on religious figures blamed on Mosaddegh’s supporters to inflame public opinion. A first coup attempt on 15–16 August 1953 failed; Mosaddegh’s forces arrested key conspirators. Roosevelt improvised a second attempt four days later using a larger network of paid agitators and military loyalists. On 19 August, mobs — many paid by CIA funds — attacked government buildings. Mosaddegh was arrested, tried for treason, and sentenced to three years’ house arrest, where he remained until his death in 1967.
Long-Term Consequences
The Shah’s restored regime became a key Western ally but governed with increasing repression, backed by the CIA-trained secret police SAVAK. Growing resentment culminated in the 1979 Islamic Revolution, which expelled the Shah, established an anti-Western theocracy, and took 52 American diplomats hostage for 444 days. Many historians and analysts trace the roots of ongoing US-Iran antagonism directly to the 1953 coup.
In 2013, the CIA released a formerly classified internal history of the coup — the first official US acknowledgement. Britain’s formal acknowledgement came later, with senior UK officials confirming MI6’s role in public statements to the House of Commons.