Operation AJAX 

ABCD
In August 1953, Iran's prime minister Mosaddeq was removed from power in a coup supported and funded by the British and U.S. governments. Mossadeq's cardinal sin was that he had the audacity to nationalize British imperial property in Iran in 1951 in the form of the British-owned Anglo-Iranian Oil Company, which had a monopoly over this most important Iranian asset for more than four decades. To punish Iran, the west imposed an embargo on her sale of oil. The ensuing economic hardship created a climate of disaffection and subversion, which set the stage for the US/UK-backed 'Operation AJAX' and the removal of Mossadeq from office by force. 

'Operation AJAX' was drafted by the American CIA. The operation started with a propaganda campaign against Mosaddeq within his government by members heavily-bribed by the CIA. Mosaddeq dissolved the parliament and organized a national plebiscite, in which he won 99.93% of the vote. In August 1953, the Shah succumbed to the CIA plot, having been told by CIA guru Kermit Roosevelt (grandson of Teddy) that the U.S. would proceed with him or without him. As a precautionary measure, he flew to Rome, and signed two decrees, one dismissing Mosaddeq and the other nominating the CIA's choice, General Fazlollah Zahedi, former Minister of Interior in Mosaddeq's cabinet, as Prime Minister. These decrees were written by Donald Wilbur, the CIA architect of the plan. 

Soon, massive protests, engineered by Roosevelt's team, took place across Tehran and elsewhere with tribesmen paid to assist the coup. Fake anti- and pro-monarchy protesters, both paid by Roosevelt, violently clashed in the streets, looting and burning mosques and newspapers, leaving almost 300 dead. Fazlollah Zahedi joined with underworld figures to gain the upper hand late August 1953. Pro-Shah tank regiments stormed Tehran and bombarded Mosaddeq's official residence, on Roosevelt's cue. Mosaddeq managed to flee from the mob but, the following day, surrendered to General Zahedi, who was meanwhile set up by the CIA with makeshift headquarters at the Officers' Club. Mosaddeq was arrested and transferred to a military jail shortly after. Shortly after the return of the Shah, end August 1953, from his flight to Rome, Mosaddeq was tried by a military tribunal for high treason. and received a sentence of 3 years in solitary confinement at a military jail and was exiled to his village not far from Tehran, where he remained under house arrest until his death in 1967. Zahedi's new government soon reached an agreement with foreign oil companies to form a consortium restoring the flow of Iranian oil to world markets. In return, the U.S. massively funded the Shah's resulting dictatorship, including his army and secret police force, known for its torture, to ensure that no other Mossadeqs would ever arise in Iran again. 

August 1953 marked the end of Iran's first experiment with parliamentary democracy. The coup restored unrestrained royalist rule. The Shah established martial law until 1957, meted out harsh treatment to those who had defied him and his Western masters, and never allowed any degree of political development to take effect in the country. The US meanwhile increased its aid to the coup regime from $33 million between 1946 and 1952 to $501 million between 1953 and 1957. 'Operation Ajax' served as a rallying point in anti-US protests during the 1979 Iranian revolution.