Having understood the mindset and groundwork of US foreign policy, i.e. theories of containment and the implications of NSC-68, the attitude of the United States and its subsequent decisions towards challenges should come as no surprise.
On June 25, 1950, following a series of border altercations on the thirty-eighth parallel and an ensuing invasion, war between North and South Korea broke out. The region, split into two contesting ideologies — a communist north and democratic south — became the perfect stage for a proxy war. Both parties demanded governmental legitimacy and control over all of Korea and believed that the border between the two was inconclusive. Understanding that Communist China and the Soviet Union would step in and support the North, the US was faced with a critical decision. Truman and the rest of the administration, along with the support of the United Nations Security Council, stepped in to support the democratic south.
Following two months of warfare, the South Korean forces along with the supporting US troops found themselves at the brink of defeat in what was known as the Pusan Perimeter—the SE edge of the Korean peninsula. After one month of defensive fighting, the southern forces and United Nations troops launched a counter-offensive strike forcing the northern troops to retreat back passed the original border and on towards the Yalu River bordering China. In October, Chinese forces crossed the river into the North Korean region and forced a retreat of South-UN forces. The following two years were consumed with a war of attrition, neither party giving up its claim of ideological and total governmental dominance. By 1953, the fighting ended in the same place where it began, the thirty-eighth parallel. The resulting armistice agreement was viewed by the US as a tie only to serve as fuel for committing troops and political rhetoric in the next challenge.
The International Review 