The Central Intelligence Agency's role in the overthrow of Mohammad Mossadegh has long been known, with the coup haunting relations between the United States and Iran six decades later.
But George Washington University's National Security Archive -- which obtained the documents under the Freedom of Information Act, a law that promotes government transparency -- said that a secret internal history marked the most explicit CIA admission.
"The military coup that overthrew Mosadeq and his National Front cabinet was carried out under CIA direction as an act of US foreign policy," the document said, using an alternative spelling of Mossadegh.
After taking office in 1953, US president Dwight Eisenhower voiced more sympathy for the British position than had the previous administration of president Harry Truman which had encouraged the US allies to compromise with Iran.
The internal CIA history, released by the National Security Archive on Sunday to mark the coup's 60th anniversary, offered a degree of understanding of Mossadegh's position and rejected Western media depictions of him as "a madman" or "an emotional bundle of senility."
But the CIA history cast the decision in Cold War terms, fearing that the Soviets would invade and take over Iran if the crisis escalated and Britain sent in warships -- as it would do three years later alongside France and Israel when Egypt nationalized the Suez Canal.
"Then not only would Iran's oil have been irretrievably lost to the West, but the defense chain around the Soviet Union which was part of US foreign policy would have been breached," it said.
