Causes of the Cold War The Cold War occurred during a time of rebuilding for Europe. It characterized international relations and dominated the foreign policies of Europe. It affected all of Europe and determined lasting alliances. The Cold War was caused by the social climate and tension in Europe at the end of World War II and by the increasing power struggles between the Soviet Union. Economic separation between the Soviets and the west also heightened tensions, along with the threat of nuclear war. One main conflict between the Soviet Union was the vast ideological differences. One of the main tenets of communism is that capita