The Cold War was the opposite of a Hot War. It was a conflict between the United States and the Soviet Union, which lasted from the 1940s through the 1990s, but it was always fought by proxy (Cuba, North and South Vietnam, East and West Germany, Afghanistan, etc.). The United States and the Soviet Union never directly fought each other, in large part because of the fear of nuclear weapons, which both countries possessed in large numbers. The Cold war can be considered more a "diplomatic war" then a real one. In part, the Cold War was based on Realpolitik, the control of land and resources in Western and Eastern Europe, but it was also a battle of ideologies. It was a war between democracy and communism, between capitalism and state-planned economies.

For a number of years Britain, Russia and the United States had discussions among themselves in an attempt to agree on the principles according to which a defeated Germany was to be treated. It had been relatively easy to establish a consensus on certain "negative" aims. Thus there was no question that Germany must be demilitarized and her war industries destroyed. Those primarily responsible for unleashing the Second World War and for perpetrating war crimes were to be brought to justice. All other Germans were to be de-Nazified. The Allies also agreed that Austria, Poland and Czechoslovakia were to be reconstituted as sovereign states.