The Iran crisis in 1946 stemmed from a Soviet refusal to relinquish Iranian territories occupied by the Red Army since 1942. The Shah of Iran, Reza Shah Pahlavi, was known to harbor pro-German sympathies, so, after the Nazi invasion of the USSR in 1941, the United Kingdom and the Soviet Union occupied Iran as a preventative measure. The Shah was deposed and sent into exile in Mauritius. His son, Mohammad Reza Pahlavi, assumed the Peacock Throne as the new king. Throughout the rest of the war, the United Kingdom and the United States used Iran as an important supply line to the Soviet war effort against Germany.
The occupation of Iran was scheduled to end after the German surrender, but, when the war ended in 1945, Soviet leader Joseph Stalin refused to withdraw Soviet forces from Iranian territory. Moreover, he attempted to partition Iran and establish two "People's Democratic Republics" on Iranian territory, the Azerbaijan People's Republic headed by Sayyid Jafar Pishevari and the Kurdish Republic of Mahabad under president Pesheva Qazi Muhammad.
Under intense pressure from the United States, the Soviet Union was forced to withdraw the Red Army from Iran. The Iranian army re-occupied Mahabad and Azerbaijan. The leaders of the Azerbaijan enclave in Iran fled to the Azerbaijan SSR, and the leaders of the Kurdish Republic were tried and sentenced to death. They were hanged in Chwarchira Square in the center of Mahabad in 1947.