The document summarizes the early stages of the Cold War between the US and Soviet Union from 1945-1955. It describes the aims and motivations of both sides in the aftermath of WWII. Key events that heightened tensions included the Soviets installing communist governments across Eastern Europe, which prompted the US policy of containment and creation of institutions like NATO to counter Soviet expansionism. An arms race and competition for influence in the developing world emerged between the two nuclear-armed superpowers.