Following the end of the Second World War, both the United States and the Soviet Union emerged victoriously as leading world powers. The United States and the Soviet Union held vastly different ideological, economic, and political views which led to their long descent as adversaries during the Cold War. The Soviet Union violated their promises they made during the Yalta Conference and proceeded to impose a communistic political system on the nations of Eastern Europe. President Truman responded by creating the "Containment Policy," this policy operated under the ideals that if communism were to exist, then it must be prevented from spreading into other countries. A manifestation of this policy came in the form of the Truman Doctrine of 1947,