I believe the Cold War between US and Soviet Union began after World war II. Both countries have a mutual distrust of each other primarily due to a couple of reasons. The Soviet Union leader's Stalin at the time had a tyrannical and communism tendencies in ruling Soviet Union and his post war communism expansion efforts in Eastern Europe made the US feared the Soviet Union had intention to control the part of Eastern Europe. It became foreign policy for US to contain Soviet Union communism expansion tendencies. The Cold War resulted to both countries competitiveness on arms race and space race.
