The history of the Korean War is long and complex, involving several decades of foreign rule prior to the conflict, and the involvement of dozens of nations during the actual fighting.
Some could argue the history of the Korean War began in 1876, when the Japanese first got involved in the region by forcing the Koreans to sign the Treaty of Ganghwa. Japan made Korea its protectorate in 1905, and officially annexed the peninsula in 1910. Japan then officially ruled the Korean peninsula until September 2, 1945, when they were forced to give up rule by the Allied Powers for losing World War II. Korea was then divided into North and South along the 38th parallel. The Soviet Union occupied North Korea after World War II, while the United States occupied South Korea. Under Allied rule, North and South quickly became divided, and the Korean War became imminent soon after.
War in Korea inched closer to reality in 1948, when a failure to hold democratic elections led to the North installing a Communist government. Tension intensified between North and South, even during reunification talks. The 38th parallel increasingly became a political border, as both sides conducted skirmishes and raids on targets just over the border. Finally, the North invaded the South on June 25, 1950, and the Korean War officially began. It was the first armed conflict of the Cold War.
The Korean War was a "war by proxy" between the United States and the Soviet Union, in which both sides backed opposing forces in a war, instead of fighting each other directly. In the history of the Korean War, however, Soviet and American troops did not fire on each other.
South Korea was officially backed by the United Nations, who aided the effort in repelling the North. The United Nations forces backed the North behind the 38th parallel, nearly to the Yalu River, until the Chinese officially entered the war in Korea. With Chinese aid, the U.N. forces were pushed back near the 38th parallel in 1951. From 1951 to 1953, little ground was gained by either side in the Korean War.
United States involvement in the war in Korea occurred primarily because of the American view of Korea as a strategic ally against the communist Chinese and Soviets. President Truman also viewed non-action in Korea as the beginning of the downfall of the United Nations, where Communism would be free to spread unchecked across the globe. Final approval to send US forces came when an intercepted communication from the Soviets stated that it would not act against US ground troops during the war in Korea. The United States officially entered the Korean War in July 1950.
Both sides ceded territory to the other quite often early in the war, until the front stabilized in 1951 near the original border at the 38th parallel. From then, very little ground was gained by either side and casualties kept rising with little to show for it. American officials raced to discuss an armistice with the North, fearing that increasing tensions with China and the Soviet Union would lead into World War III. The Korean War officially ended on July 27, 1953, after more than two long and frustrating years of negotiations.
The war in Korea led to more than 5 million combat and civilian casualties all told. The history of the Korean war is somewhat forgotten in American history, being sandwiched between the two biggest US conflicts-- World War II and Vietnam. However, the Korean War claimed the lives of more than 54,000 American troops, on par with Vietnam although in a much shorter time. Chinese and Korean casualties were nearly 10 times that of the United States. The war in Korea led to tensions between the North and South which persist to this day, although the history of the Korean War is remembered differently by each side. All-out warfare has not occurred between North and South since the end of the original conflict.
Author bio: This history of the Korean War was written by Erik Allermann. Erik lives in Watertown, Wisconsin with his wife and son. He is a 2004 graduate of the University of Wisconsin-Whitewater.