The Anglo-Soviet invasion of Iran, also known as the Anglo-Soviet invasion of Persia or the Allied invasion of Iran, was the joint invasion of the officially neutral Imperial State of Iran by the United Kingdom and the Soviet Union in August 1941. The two powers announced that they would stay until six months after the end of the war with their mutual enemy, Nazi Germany, which turned out to be 2 March 1946. On that date the British began to withdraw, while the Soviet Union delayed until May, initially citing "threats to Soviet security", followed by the Iran crisis of 1946.