The Korean War began in 1950 when North Korea invaded South Korea, supported by the Soviet Union and China. United Nations troops led by the United States intervened to defend South Korea. Fighting seesawed back and forth across the Korean Peninsula over the next two years, eventually stabilizing along the original border between North and South Korea. An armistice was signed in 1953, dividing Korea along the 38th parallel and ending direct conflict, though the two Koreas remain separate states to this day with US troops still stationed in South Korea.