US Army Task Force Smith was dispatched from Japan to aid in the South's defence, but was defeated at Osan on 5th July and joined the ROKA in its retreat.
By August 1950 the KPA had conquered most of South Korea, with the ROKA controlling only 10% of the country - the city of Pusan and the area around it up to the Nakdong River. All hope seemed lost until General MacArthur, the US military commander, proposed a daring counter attack far behind enemy lines at Inchon, just west of the capital Seoul.
On 15th September 1950, over 40,000 U.S. soldiers made an amphibious landing at Incheon and reclaimed Incheon, Seoul, and most of the northern part of South Korea. The KPA was therefore trapped between the coalition forces in Incheon and Pusan. The coalition forces soon drove the KPA out of South Korea and back across the 38th Parallel.
This part of the war marked a critical moment in US foreign policy – the decision had to be made whether to settle for successfully defending South Korea from communism, or to invade North Korea as well to defeat communism once and for all in the Korean peninsula. The possibility of a decisive victory in the fight against communism was indeed tempting to the U.S. government, as it would serve to show America’s power and dedication to halting communism in the Cold War. Also, if communism was successfully defeated in North Korea, then U.S. foreign policy in the future could potentially shift from containing communism, to actually causing it to regress.
So in October 1950, coalition forces crossed the 38th Parallel and invaded North Korea. By 19th October, the North Korean capital of Pyongyang was in coalition hands, and the coalition was quickly driving the North Korean Army further and further north towards the Yalu River – the border between North Korea and China. The US government advised MacArthur to not provoke China into entering the war by violating their border, though MacArthur argued that Chinese bases just beyond the Yalu River were important supply points for the North Korean Army, and should therefore be destroyed. This signaled the start of a major turning point in the Korean War.
This provoked the Chinese forces in Manchuria to cross into North Korea and make first contact with coalition forces on 25th October 1950. Although almost 70% of the Chinese forces were from the People’s Liberation Army (China’s official military organisation), they were named the Peoples Volunteer Army (PVA). The reason for the Chinese forces all being ‘volunteers’ instead of regular army was to avoid the possibility of open war with the US and its allies.
Chinese forces succeeded in continually driving the coalition back beyond the 38th Parallel. This marked the longest retreat of American military forces in history. Fortunately for coalition forces, the PVA stopped their advance after recapturing Seoul on 4th January 1951, due to supply issues – all Chinese supplies were carried by bicycle or on foot from the Yalu River. This gave the coalition forces the time they needed to regroup, and by 14th March 1951, they had recaptured Seoul from Chinese forces and driven the PVA back just beyond the 38th Parallel where a stalemate effectively existed for the remainder of the war until an armistice was signed on 27th July 1953.
The war ended, restoring the border between the Koreas near the 38th Parallel. The Demilitarized Zone (DMZ) was created to act as a 2.5 mile wide buffer zone; along with the Joint Security Area (JSA) where both sides could meet on neutral ground for diplomatic reasons. Despite this, there have been numerous clashes over the years - ranging from military warfare to political assassination.
