"In 1951, Mohammad Mosaddegh was elected Prime Minister of Iran, voted in by the legislature and confirmed by the Shah. Mosaddegh became enormously popular after he nationalized the oil industry of Iran, which had been largely controlled by foreign interests. He worked to weaken the monarchy of Mohammad Reza Pahlavi until Mosaddegh was removed in the 1953 Iranian coup d'état—initially an Anglo-American covert operation that marked the first time the United States had participated in an overthrow of a foreign government during the Cold War"

https://en.wikipedia.org/wiki/Iran#1951–1978:_Mosaddegh,_Mohammad_Reza_Pahlavi

There's a reason Iranians call the US The Great Satan.