After World War II, Korea was divided into North Korea and South Korea at the 38th parallel as a product of the Cold War between the Soviet Union and the United States. Both Korean governments claimed to be the legitimate government of Korea, and neither side accepted the border as permanent. A civil war erupted when North Korea, supported by the Soviet Union and China, invaded South Korea on 25 June 1950 to unite the country. The United Nations Security Council dispatched United Nations forces to Korea, and 21 countries sent troops to defend South Korea, with the United States providing 88% of United Nations military personnel. After two months, United Nations forces were at the point of defeat, backed into the Pusan perimeter. In September 1950, a brilliant amphibious counter offensive led by General Douglas MacArthur at Inchon forced the North Koreans to the border with China at the Yalu River. In October 1950, millions of Chinese forces entered the war. The last two years of war became a war of attrition, with the front line close to the 38th parallel. An armistice was signed on 27 July 1953 creating the Korean Demilitarized Zone. No peace treaty has been signed, and the two Koreas are technically still at war. United States losses were 36,574 died, 103,284 wounded, 7926 missing, and 4714 prisoners of war. 2.5 million Korean civilians were killed or wounded.