The Iran crisis of 1946, also known as the Azerbaijan crisis in Iranian sources, was one of the first crises during the aftermath of World War II, sparked by the refusal of Joseph Stalin's Soviet Union to relinquish occupied Iranian territory despite repeated assurances. The end of World War II should have resulted in the end of the Allied joint occupation of Iran. Instead, pro-Soviet Iranians proclaimed the separatist Azerbaijan People's Government and the Kurdish separatist Republic of Mahabad. The United States pressure on the Soviet Union to withdraw is the earliest evidence of success with what would become the new strategy of the Truman Doctrine and containment.