After World War II, Korea, a Japanese colony since 1910, was divided at the 38th parallel: Soviet troops in the north, American troops in the south. Two governments formed, each claiming the whole country.
Key idea
North Korea invaded South Korea in June 1950. UN forces led by the U.S. fought North Korean and later Chinese armies. An armistice in 1953 left Korea divided near the 38th parallel, with no peace treaty.
Why it works
Truman saw the invasion as a test of containment. The UN Security Council, which the Soviets were boycotting, called on members to help South Korea, so this became a UN action with U.S. forces in the lead; Congress never declared war. In September 1950 General Douglas MacArthur's landing at Inchon drove the North Koreans back, and UN forces pushed toward the Chinese border. Then hundreds of thousands of Chinese troops entered and drove them south again. MacArthur publicly called for widening the war against China; Truman relieved him of command in April 1951, upholding civilian control of the military. The war settled into two years of fighting near the 38th parallel while talks went on.
Work it through
Worked example: Counting the cost
About 36,500 Americans died in combat in Korea (some 54,000 military deaths in all, by the official count). Why does a war that ended where it began still matter?
- It was the first armed clash of the Cold War and kept South Korea independent.
- It led the U.S. to build up its military and keep troops in Asia.
- It ended in an armistice, not a treaty, so the two Koreas remain technically at war.
Answer: It defended South Korea, expanded the military, and left a divided peninsula.
Common mistake
Many students think the Korean War ended with a peace treaty or a victory. It ended in an armistice (a cease-fire agreement) in July 1953, and Korea remains divided along a demilitarized zone near the 38th parallel.
Truman's firing of MacArthur, a popular war hero, is a classic example of a constitutional principle: the President, an elected civilian, commands the armed forces.