Role of China
The United Nations and the Republic of Korea had started to expected that both sides of Korea would soon unite. On November 25th, 1950, Communist China attacked back, devastating South Korean and U.S forces and forcing the United Nation to withdraw southwards. On November 27th, near the North Korea's Chosin Reservoir, the Chinese attacked the First Marine Division and the U.S. Army task force. This resulted in one of history's greatest feats of arms. Over the course of 2 weeks, the Marine moved towards Hungnam. from which they would be evacuated by sea. China sided with North Korea during this particular war. Of course, this meant they were against South Korea and the United States. There had been many attacks/ battles between the two. China had defeated the United Nations numerous of times. This caused devastations and many casualties amongst the UN.
Implications
China had a major role in the Korean War. Based off of the resources I have found online, China had been a lot of help towards the North Korean. Since China is such a huge country with many war goods and a large army, it made it very difficult for the opposing side to defeat them. This was a huge benefit towards North Korean and it is what probably kept the war going. I believe that if it wasn't for China, North Korea would be defeated very easily (since it is a small country like South Korea) and the war would have ended much earlier.