In the aftermath of the major Chinese People's Volunteer Army (PVA) victory at the Battle of the Ch'ongch'on River, the United Nations Command (UN) started to contemplate the possibility of evacuation from the Korean Peninsula. Chinese Communist Party chairman Mao Zedong ordered the Chinese People's Volunteer Army to cross the 38th Parallel in an effort to pressure the UN forces to withdraw from South Korea.

On December 31, 1950, the Chinese 13th Army attacked the Republic of Korea Army (ROK)'s 1st, 2nd, 5th and 6th Infantry Divisions along the 38th Parallel, breaching UN defenses at the Imjin River, Hantan River, Gapyeong and Chuncheon in the process. To prevent the PVA forces from overwhelming the defenders, the US Eighth Army now under the command of Lieutenant General Matthew B. Ridgway evacuated Seoul on January 3, 1951.