Honestly I don't see nuclear powers escalating to nuclear attack when they're adjacent to each other. Nuke Beijing and the fallout's heading north back to RU lol. And they each have an arsenal, so nuke beijing, goodbye moscow.

but same, I'd be happy as a pig in shit.

thing is, it makes sense for these former communist countries to be at each other's throats, and they've had literal armed conflict before - https://en.wikipedia.org/wiki/Sino-Soviet_border_conflict we just need to point out to China that it's the path of least resistence and greatest return. They'll never be able to squeeze out the sq km's or resources going north could provide by invading Taiwan and trying to dominate the south pacific.