Chinese forces intervene in Korean War
The United Nations troops drove the North Koreans back past the 38th parallel.
Urban combat in Seoul, 1950, as U.S. Marines fight North Koreans holding the city
The UN forces crossed into North Korea in early October 1950. The U.S. X Corps made amphibious landings at Wonsan and Iwon, which had already been captured by South Korean forces advancing by land. The Eighth U.S. Army, along with the South Koreans, drove up the western side of Korea and captured Pyongyang on October 19. By the end of October, the North Korean Army was rapidly disintegrating, and the UN took 135,000 prisoners.
The UN offensive greatly concerned the Chinese, who worried that the UN forces would not stop at the Yalu River, the border between North Korea and China, and might extend their rollback policy into China. Many in the West, including General MacArthur, thought that spreading the war to China would be necessary and that since North Korean troops were being supplied by bases in China, those supply depots should be bombed. However, Truman and the other leaders disagreed, and MacArthur was ordered to be very cautious when approaching the Chinese border.
General MacArthur issues a surrender demand that North Korea surrender. China's Cho En-lai warns "The Chinese people will not tolerate foreign aggression and will not stand aside should the imperialists wantonly invade territory of their neighbor."
The ROK 3rd Division on Korea's east coast pursues communist troops across the 38th Parallel with no resistance. An American Army observation plane dropped orders to them allowing entry into North Korea. The 3rd Division had pursued the enemy since they began retreating following the U.S. Inchon invasion. The Capital Division follows soon after. Red China Premier Chou En Lai says that his government "will not stand aside" if "the imperialists wantonly invade" North Korea.