end up with two parallel governments <-- Generally speaking, that kind of thing resolves itself pretty quickly, but the resolution mechanism is just pure unadulterated power.

And invariably the side that is pro-Russia (Caleb's Law of European Politics : One side is always pro-Russia) cries "we are being oppressed, Russia please help" or something to that effect, after which the problem resolves itself once again, also, by way of pure unadulterated power.