The Tehran Conference was the first World War II conference of the “Big Three” Allied leaders. Although the leaders arrived with differing objectives, the main outcome of the Tehran Conference was the Western Allies' commitment to open a second front against Nazi Germany, including an invasion on France. The Tehran Conference caused the U.S. and Britain to invade France in May 1944. Then, the USSR would join the U.S. and Britain in the war against Japan, once Nazi Germany was defeated.
