MAP 24.2 The Korean War, 1950–1953 Considered a “police action” by the United Nations, the Korean War cost the lives of nearly 37,000 U.S. troops. Approximately one million Koreans were killed, wounded, or missing. Each side pushed deep into enemy territory, but neither could achieve victory. When hostilities ceased in 1953, a demilitarized zone near the original boundary line separated North and South Korea.