The Korean War, a significant conflict in the Cold War era, began on 25 June 1950 when North Korea, supported by China and the Soviet Union, launched an invasion into South Korea, backed by the United States and its UN allies. Hostilities arose from the division of Korea by occupying US and Soviet forces at the 38th parallel after Japan’s surrender on 15 August 1945, which ended its 35-year rule over Korea. By 1948, this division crystallized into two antagonistic states – the communist North Korea under Kim Il Sung and the capitalist South Korea under Syngman Rhee. Both regimes refused to recognize the border as permanent and claimed sovereignty over the entire peninsula.^[79]

Clashes along the 38th parallel and an insurgency in the South, supported by the North, set the stage for the North Korean invasion that triggered the war. The UN, lacking opposition from the USSR, which was boycotting the Security Council, responded by assembling a force from 21 countries, predominantly US troops, to support South Korea. This international effort marked the first major military action under UN auspices.^[80]

Initial North Korean advances pushed South Korean and American forces into a small defensive enclave, the Pusan Perimeter. A bold UN counteroffensive at Incheon in September 1950 turned the tide, cutting off and rolling back North Korean forces. However, the war's complexion changed when Chinese forces entered in October 1950, compelling the UN troops to retreat from North Korea. After a series of offensives and counteroffensives, the front lines stabilized near the original division at the 38th parallel.^[81]

Despite fierce fighting, the front eventually stabilized close to the original dividing line, resulting in a stalemate. On 27 July 1953, the Korean Armistice Agreement was signed, creating the DMZ to separate the two Koreas, although a formal peace treaty was never concluded. As of 2018, both Koreas have shown interest in formally ending the war, demonstrating the ongoing nature of the conflict.^[82]

The Korean War was one of the most devastating conflicts of the 20th century, with civilian casualties exceeding those of World War II and the Vietnam War, significant atrocities committed by both sides, and widespread destruction in Korea. Approximately 3 million people died in the conflict, and the bombings left North Korea extensively damaged. The war also prompted the flight of 1.5 million North Koreans, adding a significant refugee crisis to the war’s legacy.^[83]