The document provides background information on the origins of the Cold War between the United States and Soviet Union following World War II. It discusses the formation of the United Nations near the end of WWII to prevent future global wars. Tensions rose as the Soviet Union failed to withdraw from Eastern Europe and instead imposed communist control over countries like Poland and East Germany. The ideological differences between capitalism in the West and communism in the East, as well as mutual distrust between the US and USSR, marked the beginning of the Cold War that lasted from 1945-1991.