In August 1953, the CIA (Operation Ajax) and British MI6 (Operation Boot) orchestrated the overthrow of Iran's democratically elected Prime Minister Mohammad Mossadegh and restored Shah Mohammad Reza Pahlavi to full power. The CIA acknowledged its role in a 2013 declassified internal history. The coup followed Mossadegh's nationalisation of the Anglo-Iranian Oil Company (AIOC) and is widely regarded as a foundational event in modern Iranian-US relations, contributing to the conditions that produced the 1979 Islamic Revolution.