Why did south vietnam need us assistance in the early me

South Vietnam needed the US assistance in the early 1960´s because North Vietnam at that time was supported by the Soviet Union, China and other communist countries fighting against South Vietnam with no possibility of containing the communist advance.

After the US withdrew from the conflict, the entire region was taken under the communist government.

cultural/diplomatic relations. most medieval japanese   culture has chinese origins. writing, architecture etc.

uncle sam would be tossing and turning in his grave : *)