In retrospect, the United States sponsored coup d'état in Iran of August 19, 1953, has emerged as a critical event in postwar world history. The government of Prime Minister Mohammad Mosaddeq which was ousted in the coup was the last popular, democratically oriented government to hold office in Iran. The regime replacing it was a dictatorship that suppressed all forms of popular political activity, producing tensions that contributed greatly to the 1978–1979 Iranian revolution. If Mosaddeq had not been overthrown, the revolution might not have occurred. The 1953 coup also marked the first peacetime use of covert action by the United States to overthrow a foreign government. As such, it was an important precedent for events like the 1954 coup in Guatemala and the 1973 overthrow of Salvador Allende in Chile, and made the United States a key target of the Iranian revolution.