 Complete the following phrase:  During the rest of World War II, Iran became a major conduit for British and American aid to the Soviet Union and an avenue through which over 120,000 Polish refugees and Polish Armed Forces fled the Axis advance. At the 1943 Tehran Conference, the Allied Big ThreeJoseph Stalin, Franklin D. Roosevelt, and Winston Churchillissued the Tehran Declaration to guarantee the post-war independence and boundaries of Iran. However, at the end of the war, Soviet troops remained in Iran and established two puppet states in north-western Iran, namely the Peoples Government of Azerbaijan and the Republic of Mahabad. This led to the 