Lead-up to Tehran

Key Issue:  One of the major issues that the Allies would confront at both Tehran and Yalta concerned Poland. At the beginning of the war, the Soviet Union gained control of Eastern Poland when Germany invaded Poland as part of the Nazi-Soviet Pact. In response to the German Soviet 1939 invasion, a Polish government in exile took root in London to work towards an independent Poland. After the German attack on Russia in 1941, the Soviets recognized the Polish government in exile. However, in April of 1943, the Germans unearthed of a mass grave hiding the massacre of 14,000 Polish officers, which the London Polish government blamed on Russia. This led Stalin to terminate communication with the London Poles and eventually  establish a puppet government in Lublin, Poland, leaving the Anglo Americans with a dilemma: do they recognize the Lublin Poles or the London Polish government? A second issue involved the borders of Poland. Stalin wanted the eastern border of Poland to follow the Curzon Line, the same border that had been established in the Nazi Soviet Pact. The London Poles staunchly opposed this, but both Churchill and Roosevelt were more flexible on this issue, provided Poland be compensated with additional territory in the west.