On June 25 1950, the Korean War began when 75000 soldiers from the North Korean People’s Army poured across the 38th parallel, the boundary between the Soviet-backed Democratic People’s Republic of Korea to the north and the pro-Western Republic of Korea to the south. This invasion was the first military action of the Cold War.
Since the beginning of the 20th century, Korea had been a part of the Japanese empire, and after World War II it fell to the Americans and the Soviets to decide what should be done with their enemy’s mperial possessions. In August 1945, two young aides at the State Department divided the Korean peninsula in half along the 38th parallel. The Russians occupied the area north of the line and the United States occupied the area to its south.
By the end of the decade, two new states had formed on the peninsula. In the south, the anti-communist dictator Syngman Rhee (1875-1965) enjoyed the reluctant support of the American government; in the north, the communist dictator Kim Il Sung (1912-1994) enjoyed the slightly more enthusiastic support of the Soviets. Neither dictator was content to remain on his side of the 38th parallel, however, and border skirmishes were common. Nearly 10,000 North and South Korean soldiers were killed in battle before the war even began.
Even so, the North Korean invasion came as an alarming surprise to American officials. As far as they were concerned, this was not simply a border dispute between two unstable dictatorships on the other side of the globe. Instead, many feared it was the first step in a communist campaign to take over the world. For this reason, nonintervention was not considered an option by many top decision makers. (In fact, in April 1950, a National Security Council report known as NSC-68 had recommended that the United States use military force to “contain” communist expansionism anywhere it seemed to be occurring, “regardless of the intrinsic strategic or economic value of the lands in question.”)
The fight on the Korean peninsula was a symbol of the global struggle between east and west, good and evil. As the North Korean army pushed into Seoul, the South Korean capital, the United States readied its troops for a war against communism itself.
At first, the war was a defensive one–a war to get the communists out of South Korea–and it went badly for the Allies. The North Korean army was well-disciplined, well-trained and well-equipped; Rhee’s forces, by contrast, were frightened, confused, and seemed inclined to flee the battlefield at any provocation. Also, it was one of the hottest and driest summers on record, and desperately thirsty American soldiers were often forced to drink water from rice paddies that had been fertilized with human waste. As a result, dangerous intestinal diseases and other illnesses were a constant threat.
By the end of the summer, President Truman and General Douglas MacArthur (1880-1964), the commander in charge of the Asian theater, had decided on a new set of war aims. Now, for the Allies, the Korean War was an offensive one: It was a war to “liberate” the North from the communists.
Initially, this new strategy was a success. An amphibious assault at Inchon pushed the North Koreans out of Seoul and back to their side of the 38th parallel. But as American troops crossed the boundary and headed north toward the Yalu River, the border between North Korea and Communist China, the Chinese started to worry about protecting themselves from what they called “armed aggression against Chinese territory.” Chinese leader Mao Zedong (1893-1976) sent troops to North Korea and warned the United States to keep away from the Yalu boundary unless it wanted full-scale war.
In July 1951, President Truman and his new military commanders started peace talks at Panmunjom. Still, the fighting continued along the 38th parallel as negotiations stalled. Both sides were willing to accept a ceasefire that maintained the 38th parallel boundary, but they could not agree on whether prisoners of war should be forcibly “repatriated.” (The Chinese and the North Koreans said yes; the United States said no.) Finally, after more than two years of negotiations, the adversaries signed an armistice on July 27 1953. The agreement allowed the POWs to stay where they liked; drew a new boundary near the 38th parallel that gave South Korea an extra 1500 square miles of territory; and created a 2-mile-wide “demilitarized zone” that still exists today.
The Korean War was relatively short but exceptionally bloody. Nearly 5 million people died. More than half of these–about 10 percent of Korea’s prewar population–were civilians. (This rate of civilian casualties was higher than World War II’s and Vietnam’s.) Almost 40000 Americans died in action in Korea, and more than 100000 were wounded.