Its really hard to see what his endgame actually is. Do we go all out and give him a new cold war? would that be playing into his hands, and give him the excuse to do a total arms build up sort of thing.
Or just ignore and do incremental escalation? Where is the chocolate wheel.
What I do know though, there is a country doing its best to behave and getting screwed over by Russia and we won't give them so much as bullets!