"56,000 dead. For nothing."
Simply not correct. The major rationale for fighting in South Vietnam was to stop the spread of communism into SE Asia, Indonesia, the Phillipines, and ultimately Japan and Australia. South Vietnam fell when the liberals in Congress cut off all funds and support to the country when it was being invaded by the North. What rolled into Saigon were not peasants trying to liberate their country but well equipped regular armored divisions from North Vietnam.
Ultimately South Vietnam fell. But the communists paid such a high price for it that revolutionary export went out of fashion, and the dominos never fell. For that, we can thank the brave men and women who fought there from many countries. They were robbed of their victory in South Vietnam by the politicians back home; but their more important legacy is a major part of the Asian-Pacific theatre that never fell to communism.
Ultimately South Vietnam fell.
2 years after
all combat troops were withdrawn by Jan, '73.......
commies "took" Saigon in Apr, '75.