The Korean War was an armed conflict fought on the Korean Peninsula between North Korea and South Korea and their allies. North Korea was supported by China and the Soviet Union, while South Korea was supported by the United Nations led by the United States under the auspices of the United Nations Command (UNC). The conflict was one of the first major proxy wars of the Cold War and one of its deadliest conflicts on non-combatants, as it is estimated that 1.5 to 3 million civilians were killed during the war. The war was the first time the United Nations Security Council authorized the use of force under Chapter VII of the United Nations Charter.