Korean War

The Korean War originated in the division of Korea into South Korea and North Korea after World War II (1939-1945). Efforts to reunify the peninsula after the war failed, and in 1948 the South proclaimed the Republic of Korea and the North established the People’s Republic of Korea. In 1949 border fighting broke out between the North and the South. On June 25, 1950, North Korean forces crossed the dividing line and invaded the South. Soon, in defense of the South, the United States joined the fighting under the banner of the United Nations (UN), along with small contingents of British, Canadian, Australian, and Turkish troops. In October 1950 China joined the war on the North’s side. By the time a cease-fire agreement was signed on July 27, 1953, millions of soldiers and civilians had perished. The armistice ended the fighting, but Korea has remained divided for decades since and subject to the possibility of a new war at any time.

Division of Korea
The Korean War was the result of the division of Korea, a country with a well-recognized, ancient integrity. Despite its long history as an independent kingdom, Korea had been forcibly annexed by Japan in 1910. Japan controlled Korea up to the end of World War II. Late on the night of August 10, 1945, as World War II was coming to a close, the United States made the decision that it would occupy the southern half of Korea. The U.S. government did so out of fear that the Union of Soviet Socialist Republics, which had joined the fight against Japan in northern Korea a week earlier—would take control of the entire Korea Peninsula. American planners chose to divide Korea at the 38th parallel because it would keep the capital city, Seoul, in the American-occupied southern zone; the USSR acquiesced to the division, with no official comment.

Both the Soviet Union and the United States proceeded, with much help from Koreans, to build regimes in their halves of Korea that supported their interests. In so doing, they had to contend with major rifts between Korean political factions representing left-wing and right-wing views. These factions originally were united against Japan but had begun to split as early as the 1920s. In the post-World War II era, the main conflict centered around the left’s call for—and the right’s resistance to—a thorough reform of Korea's land ownership laws, which had allowed a small number of wealthy people to own most of the land. As a result, many Korean farmers were forced to eke out an impoverished existence as tenant farmers.
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