lol… is the CCP paying you for this? Why the hell would China want Burna? Also, Russia nuking China is equivalent to nuking themselves. China will try the same method called salami slicing that is used against India to seize land. India can fight back and they have control of the island at the Malacca Strait exit point.Your entire premise doesn't take into account that Russia has a lot more nukes than China does.
There's no good reason for China to make a move on either Russia or any former Soviet REpublic. It's just buying trouble they don't need.
Not that China is an aggressive nation to start with, but if they were in the mood for expansion, the first place they might want to look is Myanmar (Burma). The place is in Chaos, they could plausibly claim that they were restoring the peace.
