During the Korean War:
-MacArthur was opposed to Truman's policy of containment
MacArthur led the United Nations forces that defended South Korea in 1950-1951 against North Korea's attempt to unify the country by force. MacArthur was relieved of command by President Harry S. Truman in April 1951, for his public disagreements with presidential politics.
-Chinese volunteers supported North Korea
The Chinese assault was initiated on October 19, 1950, under the command of General Peng Dehuai, when 380,000 soldiers of the People's Liberation Army repelled the UN troops and took them to the 38th parallel, the pre-conflict border. Among the Chinese volunteers was Mao Anying, Mao Zedong's eldest son, who would die in the fighting.
-U.S. Marines made a miraculous retreat from the Chosan Reservoir
The Battle of Chosin Reservoir was a decisive battle of the Korean War. Shortly after the People's Republic of China entered the conflict, the Ninth People's Army of Chinese volunteers entered the northeastern North Korea and surprised the 10th Marine Corps Division in the area of the Chosin Reservoir. Soon a brutal battle of 17 days with freezing temperatures was fought. In the period between November 27 and December 13, 1950, the 30,000 United Nations troops, under the command of Major General Edward Almond, were surrounded by some 67,000 Chinese soldiers under the command of Song Shi-Lun. Although the Chinese troops were superior in number, the UN forces managed to break the siege and withdraw, inflicting heavy losses on the Chinese side. The evacuation of US troops through the port of Hungnam meant the total and definitive withdrawal of the UN troops from North Korea.