From what I heard recently, Russia has two benefits:

1. Tactical - chokepoints are a major element of military tactics, and I guess there's a spot that leaves Russia completely defenseless with wide-open spaces if it doesn't own Poland and Ukraine.

2. Wheat - apparently, Russia owns quite a bit of the market, and Ukraine would carry another minority.

With that in mind, I see this entire thing as a coercive and brutal M&A, but with people's lives being destroyed instead of just their long-term career plans.