Who's going to stop Russia if they do roll in?
0bama? the EU? Ukrainian armed forces?
Where’s Marshall Pilsudski when we need him?
The Ukrainian fleet is harbored right next to the Russian fleet at Sevastopol-- all it would take would be a couple of Ukrainian cruisers firing point blank to cause massive damage.
Russia could undoubtedly 'win' in the end, but the cost would be massive, and would also probably involve loss of access to Western markets and cash.
The bigger danger to Ukraine are 'separatists' funded by Moscow and aided under the table with weapons or Russian special forces.