The Iran crisis of 1946, also known as the Azerbaijan Crisis () in the Iranian sources, was one of the first crises of the Cold War, 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 the new strategy of Truman Doctrine and containment.
In August–September 1941, Pahlavi Iran had been jointly invaded and occupied by the Allied powers of the Soviet Red Army in the north and by the British in the centre and south. Iran was used by the Americans and the British as a transportation route to provide vital supplies to the Soviet Union's war efforts.
In the aftermath of the occupation of Iran, those Allied forces agreed to withdraw from Iran within six months after the cessation of hostilities. However, when this deadline came in early 1946, the Soviets, under Joseph Stalin, remained in Iran. Soon, the alliance of the Kurdish and People's Azerbaijani forces, supported in arms and training by the Soviet Union, engaged in fighting with Iranian forces, resulting in a total of 2,000 casualties. Negotiation by Iranian premier Ahmad Qavam and diplomatic pressure on the Soviets by the United States eventually led to Soviet withdrawal and dissolution of the separatist Azeri and Kurdish states.
Background
After Germany broke its pact with the Soviets and invaded the USSR in June 1941, the United Kingdom and the Soviet Union jointly occupied neutral Iran as a preventive measure, starting on August 25, 1941, and justified their invasion by the need to use Iran as a gateway for delivery of Lend-Lease supplies to the Soviet Union from British India. Iran had laid torn between the concurrent zones of influence of both Britain and Russia for a long time, but had managed until then to remain independent, despite several foreign interventions, by taking advantage of the rivalry between the two rival powers. Now that they stood together against Germany, nothing longer opposed a formal joint occupation of the country. As a result, Rezā Shāh was forced to abdicate on September 16, 1941 and exiled to Mauritius; his son, Mohammad Reza Pahlavi, the crown prince, became the new monarch. Their joint 'Tripartite Treaty' of January 1942 declared that their military presence was not an occupation, proclaimed Iran to be their ally, and pledged to withdraw their troops within six months of the end of the war.
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 Nazi Germany. Thirty thousand non-combatant U.S. troops arrived to move these supplies, and transit through Iran was later termed a "bridge to victory". At the Tehran Conference in 1943, the Big Three gave additional assurances concerning Iran's future sovereignty and territorial integrity, as well as a promise to assist in its post-war reconstruction and development.
Although the occupation of Iran was scheduled to end after the war at the Potsdam Conference following Germany's surrender, Stalin objected to Churchill's proposal for an early allied withdrawal from Iran ahead of the agreed-upon schedule set at the Tehran Conference. Following VJ Day in September 1945, first the United States and then the United Kingdom withdrew their forces within the treaty-stipulated period. The Soviets not only violated the March 2 withdrawal deadline; in that time they had expanded their military presence southward. By mid-December 1945, with the use of troops and secret police, they had set up two pro-Soviet "People's Democratic Republics" within Iranian territory, the Azerbaijan People's Government headed by Sayyid Jafar Pishevari and the Kurdish Republic of Mahabad under President Pesheva Qazi Muhammad. It is another example of the Soviet Union's appropriation of Imperial Russia's geopolitical ambitions, as the disputed zone had already been occupied by Imperial Russia 35 years before, in the 1911 Russian invasion of Tabriz.