In 1949, the Communists Were Victorious in China

Korean War

during WWII , when the Soviets declared war on Japan, they immediately occupied up to the 38th parallel as agreed
US occupied the South, USSR the North
the idea of turning Korea into an independent nation was put on hold as it became a Cold War battleground

by 1949, Soviet and US troops had withdrawn, but the North maintained a strong force
on June 25, 1950, North Korea launched an attack on the South
the US, mindful of the lessons learned from both Appeasement and the loss of China, immediately dedicated troops
Truman was also nervous about the security of Japan
he approached the UN to get a resolution to repel the aggressors

the USSR, who had been boycotting the UN over Nationalist China (Taiwan) was not present at the meeting to veto
Korea thus became a UN security measure

Douglas MacArthur, who was in charge of the military, staged a brilliant maneuver by landing at Inchon behind North Korean forces
he drove the North out of the South towards the Chinese border
the war now became one of conquering rather than one of repelling
Chinese “volunteers” joined the North and pushed the UN back down to the 38th parallels by 1951
as the UN retreated from the North, MacArthur began to make noise
he wanted to use Taiwanese troops to help invade China
he also proposed using nuclear weapons on the North
he disagreed publicly with Truman and was ultimately removed

the war dragged on until 1953 when an armistice was signed
150 000 US, 1.25M South Korean, 2M North Korean & Chinese
many people felt slighted by the stalemate and were unhappy with the loss of China
led to the election of Eisenhower in 1952