During the Cold War, the United States and Soviet Union avoided direct military conflict by engaging in proxy wars where they supported opposing sides in regional conflicts. Some of the major proxy wars included the Greek Civil War where the US supported Greece and Soviet Union supported communists; the Korean War where the US supported South Korea and Soviet Union supported North Korea; and the Vietnam War where the US supported South Vietnam while the Soviet Union backed North Vietnam. These proxy wars increased tensions between the two superpowers as they battled for influence and control around the world during the Cold War.