We might see apocalyptic scenarios due to residual nuclear weapons, but without any ideological import, other than the final destruction of the once bastion of socialism. Vietnam is struggling to get into the global economy and seems also unlikely to be a center of periphery revolution. Each is regularly demonized in the media and favorable stories never appear. Cuba is an example of a periphery rebel-state which is sincerly motivated by democratic socialism, and in which solidarity between people and government has been largely maintained. I'd say Cuba's treatment is a microcosm of what would happen with any enlightened periphery revolutionary center that arises in future.
China is a unique case.
China is also compromising its socialist principles in order to become a bigger player globally - further moving it away from ever being an enlightened periphery center. You are not describing my position - you're not even close. This is one end of the spectrum of revolutionary focus, and I'd be happy to discuss it along with others. These core nations are mostly capitalist controlled at present, and collaboratively and systematically suppress peripheral uprisings, as discussed earlier above. What I said is that as long as core states oppose peripheral revolution, such revolution will be suppressed.