Battlefront Korea, Nov - Dec 1950 : Chinese People's Volunteer Army separated into two army groups, with Chinese Fourth Field Army in west, Chinese Third Field Army in east. Allied units in the east was squeezed into evacuation ports at HUNGNAM and WONSAN. Allied units in the west began a long retreat that did not stop until South Korea capitol Seoul was reached. Seoul eventually fell to Communist forces in Jan 1951, but recaptured by US/UN forces in March 1951. Korean War - en.wikipedia.org/wiki/Korean_war

Other events also shook US resolve. Retreat of US/UN forces seriously demoralized its troops, US Gen. Walton Walker of US Eight Army in Korea was killed in traffic accident on Dec. 1950, US/UN Supreme Commander Gen. Douglas MacAuthur was sacked by US President Truman in April 1950 after open dispute over course of Korean War. MacAuthur favored formal alliance with Nationalist Chinese troops on Taiwan, bombing of Communist Chinese sanctuary bases in Manchuria, and possible usage of tactical nuclear weapons to eliminate the Communist threat. Truman, fearful of a nuclear Third World War with Soviet Union and indignant over MacAuthur's misreading of Chinese intent, desired a negotiated peaceful solution to the conflict. Gen. Walton Walker - en.wikipedia.org/wiki/Walton_Walker

Rollover : Snapshot of rugged Korean mountains, before modern day spy satellites and UAV surveillance, such terrain hide tens of thousands of Communist Chinese. From 1951 onward, World War I-style trench warfare ensued as both sides assaulted each others fortified hilltop positions to gain favorable stance at the negotiation table. Talks dragged on until 1953 when Korean Truce was declared. Truce simply meant both sides agreed to stop fighting for now, but the war officially is not over. For the next 5 decades, tensions on Korean demilitarized zone created one incident to the next. With North Korea now possessing ballistic missile technology and nuclear weapons program, regional tensions increased exponentially in the 21st-century. Truce - en.wikipedia.org/wiki/Truce