Korean War Begins
North Korean forces crossed the 38th parallel, starting the Korean War
June 25, 1950
A Divided Peninsula Goes to War
On June 25, 1950, North Korean forces crossed the 38th parallel and invaded South Korea, beginning the Korean War. The attack came before dawn and caught South Korean and U.S. forces completely off guard. Within three days, the South Korean capital of Seoul had fallen to the North Korean People's Army. Korea had been divided along the 38th parallel after World War II, with the Soviet-backed North and the American-backed South developing as opposing political systems during the early Cold War. The invasion was almost certainly approved by Soviet leader Joseph Stalin and supported with Soviet weapons, though North Korean leader Kim Il-sung was eager for the war himself.
America and the United Nations Respond
U.S. President Harry Truman quickly committed American forces to defend South Korea. The United Nations Security Council, in an unusual session held while the Soviet Union was boycotting the body over a separate dispute, authorized a multinational force to repel the invasion. Sixteen countries ultimately contributed troops under U.S. General Douglas MacArthur's command. The war swung dramatically in the summer and autumn of 1950. United Nations forces were pushed to a small perimeter around the port city of Busan before a dramatic amphibious landing at Inchon in September 1950 reversed the momentum entirely. UN forces pushed deep into North Korea, approaching the Chinese border.
China Enters and the War Grinds On
In October 1950, hundreds of thousands of Chinese troops crossed the Yalu River and drove UN forces back below the 38th parallel. The war settled into a brutal stalemate along roughly the original dividing line. Truman fired MacArthur in April 1951 after the general publicly challenged civilian authority over war policy. Armistice negotiations began in July 1951 and dragged on for two years while fighting continued. The war killed an estimated 36,000 American troops, 137,000 South Korean soldiers, and hundreds of thousands of North Korean and Chinese soldiers, along with enormous civilian casualties. Korea remains divided today along almost exactly the same line where fighting began in 1950.