The small but more confident army that resulted from American training was capable enough to participate in the 1946 campaign in Azarbaijan to put down a Soviet-inspired, separatist rebellion. During the three years of occupation, Stalin had expanded Soviet political influence in Azerbaijan and the Kurdish area in northwestern Iran. On 12 December 1945, after weeks of violent clashes, a Soviet-backed separatist People's Republic of Azerbaijan was founded. The Kurdish People's Republic was also established in late 1945. Iranian troops sent to re-establish control were blocked by Soviet Red Army units. When the deadline for withdrawal arrived on 2 March 1946, six months after the end of hostilities, the British began to withdraw, but Moscow refused, "citing threats to Soviet security," sparking the Iran crisis of 1946. Soviet troops did not withdraw from Iran proper until May 1946, following Iran's official complaint to the newly formed United Nations Security Council and intense pressure from the United States.