Garbagacious premise.
The Nixon move to recognize China was a great event.
China is an can not be ignored. By dealing with China, Nixon flanked Russian ambitions in Vietnam and effectively ended the vietnam war. Russia was out.
[China is an can not be ignored. By dealing with China, Nixon flanked Russian ambitions in Vietnam and effectively ended the vietnam war. Russia was out.]
https://en.wikipedia.org/wiki/China_in_the_Vietnam_War#Confronting_U.S._escalation
Basically, Nixon was a crappy president except when compared to the Democratic opponents he faced. Reagan would have won in South Vietnam. The question, however, is whether he could have defeated Humphrey in 68.