The intervention of USA was more of a hindrance because the USA prolonged the war by invading into the North Korean territory when they could have actually ended the fight with the North Koreans at the 38th parallel. However the UN coalition army led by USA, under the leadership of General MacArthur, once they have reached the main objective of repelling the North Korean Army, they could have stopped there and not go further into North Korean territory. President Truman at that time, authorised MacArthur to “feel unhampered tactically and strategically to proceed north of the 38th parallel”, suggesting that USA should be rolling-back the boundaries of Communism. This resulted in the Korean War lasting longer than it could have been resulting in less casualties and collateral damage.
The intervention of USA was also a hindrance because it made the war international by getting China involved. When the UN coalition army reached the 38th parallel, China had warned that it would not sit by and watch if the UN army stepped into North Korean territory. MacArthur disregarded the Chinese warning and went further north. This provoked China because they did not have an embassy in the US and was unaware of US’s intentions on whether to further push into China. Thus, for the fear of USA invading into China, Chairman Mao sent troops to help the North Koreans in repelling the UN coalition and pushing them back to the 38th parallel. This made the war international as it was a war between many parties, namely the US, China, and North and South Korea. This resulted in further casualties between both sides as