If Putin can't sell his gas and oil at exhorbinant prices to countries like Ukraine, his budget dries up. He can't mount continuous aggression without it so he needs to get his former satellites while the getting is good.
We could go back and build the missile defense systems for the Czechs and Pols that we canceled thinking it would help the misspelled reset button from when Obama first took office. Didn't anyone see the handwriting on the wall from that one?
We could freeze the assets of Russians in this country. And of companies and countries doing business with both Russia and the U.S.
This doesn't put one military boot on the ground. We don't need NATO or UN approval. We can make hell freeze over.
Unfortunately I've not seen nor heard the will to do anything more than what the Russians do so well. Scold. The problem is, we bow our heads and slink away. They laugh like the bullies they are and take advantage of the situation.
They'll win if not challenged. If we don't, who will? We're needed. Why is it we're absent without leave? Or in more precise terms - deserters?