The document summarizes the key causes of the Cold War in 4 areas: 1) the ideological differences between communism and capitalism as embodied by the USSR and USA. 2) A history of mistrust between the USSR and Western powers from the Russian Revolution to WWII. 3) The actions of the USSR after 1945. 4) The actions of the USA after 1945. Taken together, these factors made the outbreak of the Cold War likely between the Soviet Union and the United States.