Korean War

Why did America get further involved in the Korean War?
The policy of Rollback
Following MacArthur’s masterstroke at the Inchon landings on 15 September and the subsequent retreat of North Korean back across the 38th Parallel, Truman adopted the policy of ‘rollback’, which was intended to eliminate the Communist threat from the North completely or at least find a better defensive position further north on which to dig in and defend.   This goal to drive the Communists from North Korea increased the length of the war.
US doubts over Chinese intervention
When it became clear that the USA intended to advance across the 38th Parallel, Zhou Enlai, the Chinese prime minister, summoned the Indian ambassador in Beijing to tell him that if US forces crossed the border, China would be forced to intervene.   These warnings were subsequently ignored these warnings.   Furthermore, the head of intelligence Major General Willoughby provided MacArthur with false information, claiming that the numbers of Chinese troops in Manchuria was small and their quality was insignificant, assuring that intervention would not occur.   However, when American troops advanced towards the Yalu river on the Chinese border on the 1-2 of November, 150,000 Chinese troops entered North Korea, subsequently extending the war.
Pressure from within the State Department
Within the State Department, moderate politicians were being replaced by more aggressive Cold War warriors like Dean Rusk, John Allison and John Foster Dulles.   To this new group, it was essential to respond to challenges from Moscow with a hard-hitting response in order to discourage such adventures.   This strong anti-Communist lobby was most notably enriched in the flawed claims Senator Joe McCarthy, the hard-line anti-Communist.   It was pressure from this group that contributed to the decision to extend the war beyond the 38th Parallel.
American desire to get a good resolution
While peace talks occurred at Panmunjom in 1952 and 1953,...