Invasion, Counterstrike, Invasion
On June 25, 1950, communist-backed forces from the north invaded South Korea. The United States secured a United Nations sanction against the invasion and contributed the lion’s share of troops to repel it. World War II hero Douglas MacArthur was put in command of the U.N. forces.
The North Korean troops—trained by the Soviets and the Chinese—quickly pushed the South Koreans back toward the southern tip of the Korean peninsula. MacArthur struggled to hold the critical southern port of Pusan to buy time until reinforcements arrived. He then executed a controversial landing at Inchon, on the west coast of Korea, behind North Korean lines. The landing was a stunning success—perhaps MacArthur’s single greatest military feat—and by October 1, 1950, the North Koreans had been pushed out of South Korea. U.N. forces were now arrayed along the 38th parallel.
Within the Truman administration debate raged over whether to cross the 38th parallel and invade North Korea. President Truman compromised, authorizing the crossing, but taking steps to avoid provoking the Chinese and the Soviets directly. No U.N. troops would enter Manchuria or the U.S.S.R., and only South Koreans would operate along international borders. On October 7, the U.N. General Assembly called for the unification of Korea and authorized MacArthur to invade. On October 19, the North Korean capital of Pyongnang fell, and the North Korean armies were pushed far north, to the Yalu River, the nation’s border with Manchuria.
The war seemed to be over—but then, between October 14 and November 1, some 180,000 communist “volunteers” crossed the Yalu from China. MacArthur launched an offensive on November 24, only to be beaten back by massive Chinese resistance, which pushed U.N. troops back across the 38th parallel. The South Korean capital of Seoul fell to the communists in January 1951.