History of Asia

What was the main source of tension between USSR and U.S. near end World War 2?

Eastern Europe

Although the Allies had agreed at Yalta to allow free and fair elections in Eastern Europe after the war, the Soviet Union moved quickly to install communist governments in all the countries it occupied, including Poland, Hungary, Czechoslovakia, Romania, and Bulgaria. The United States and Britain protested, and the issue became a major source of tension between the two superpowers.