You're talking about areas where people actually live, not some game of Risk.

There are enough tensions in the borderlands already. Ukraine is going to have its work cut out rebuilding when the dust settles without taking on any more problems and unstable populations.

What it will need to do is secure its access to the Black Sea. That might have been one of the spurs for Putin's aggression, having already taken Crimea. I hope he won't end up being rewarded by hanging onto it.