 Complete the following phrase:  At the Yalta Conference in February 1945, Stalin was able to present his western allies, Franklin Roosevelt and Winston Churchill, with a fait accompli in Poland. His armed forces were in occupation of the country, and his agents, the communists, were in control of its administration. The Soviet Union was in the process of incorporating the lands in eastern Poland, including the mass expulsion of the Polish population, which it had occupied between 1939 and 1941, after 