North and South Korea between the Cold War, UN intervention, and the armistice

In 1945, at the end of the Second World War, the USA and the USSR, which were occupying Korea, a former Japanese colony, divided the country along the 38th parallel: Soviet forces took control of the North, and American forces of the South. The peninsula was supposed to be governed this way for five years and then become independent; however, disagreements between the two victors made the division permanent. In 1948 the North and the South held separate elections; the following year the USA and the USSR withdrew their troops. Nevertheless, North Korea intended to reunify the peninsula under communist rule and, with tacit Soviet support but without a promise to send soldiers, attacked the South in June 1950. The invasion was unexpected and Northern troops managed to occupy almost the entire peninsula, but in July the United States, South Korea, and other allies intervened under the aegis of the UN. Under the pressure of their forces, the front moved northward, coming to a halt in November in the face of the Chinese invasion.

By mid-1951 the situation was at a stalemate; in July 1953 an armistice was reached, which provided for the withdrawal of forces from both sides of the 38th parallel. The armistice is still in force today: a definitive peace has never been signed.