Tactically Vietnam was a stunning success.
Haha, it is pathetic to be proud of a 'tactical success' against a few poors in pajamas, considering the resources the fascist invader had on its side. How on earth could the scenario not be a 'tactical success' for the overwhelming power in a situation like that?
North Vietnam had the tacit backing of the People's Republic of China. The Chinese had made it clear that they would not tolerate a US puppet state at their borders when they invaded North Korea in 1950. And since the Chinese had tested nukes in 1964, the MacArthur solution was no longer a possibility, even if military leaders had been inclined in that direction (which they wisely weren't). Even though they never fired a shot (besides providing the NVA with some anti aircraft support) their presence and the history of their intervention in Korea effectively protected the so called poors in pajamas from US attack. Also, by 1972 they were the conduit for transfers of large numbers of Soviet tanks into the NVA, and the NVA learned how to use them in 1975 to win the war.