The document summarizes the origins and key events of the Cold War between the United States and Soviet Union from 1945-1953. After being allies in WWII, political and ideological differences strained relations and led to a rivalry known as the Cold War. The Soviets installed communist governments in Eastern Europe, while the US sought to contain the spread of communism through policies like the Truman Doctrine and Marshall Plan. Conflicts in areas like Germany, China, and Korea further escalated tensions between the two superpowers.