What was the primary reason for u. s
involvement in east asia during the early 1950s

a vigilant anti-Communist foreign policy resting on four pillars: the United Nations, the Marshall Plan, NATO, and a “bold new plan” for providing financial and technical assistance to underdeveloped parts of the world, which came to be known simply as Point Four.  The United States and the Soviet Union, former allies, differed on issues of human rights, individual liberties, and self-determination, which culminated in a period called The Cold War. After a Communist government came to power in China in 1949, Korea became a “hot spot.” The peninsula had been divided at the 38th parallel after the Second World War, with a Communist regime in the North and a Western-style regime in the South. After North Korean troops crossed the dividing line in June 1950, Truman decided to go to war under the auspices of the United Nations and without asking Congress to declare war. The war was thus waged by the United States with the participation of more than a dozen member nations of the United Nations. A truce concluded in July 1953, established a demilitarized zone on either side of the 38th parallel.

becasue in the south they disallowed slavery but in the north slavery was illegial this boilled into because mexico wanted slavery

hope this

the answer is states.