With a POD sometime before 1973 that allows the survival of South Vietnam (say the US were more decisive in defeating North Vietnam during the Easter Offensive or if Watergate gets avoided), and that North Vietnam is unwilling to continue on with their reunification efforts for a while, how would the existence of South Vietnam past OTL's 1975 effect world politics?
One thing is for sure, the Indochina region would be a lot less red that's for sure.