Hmmm. You seem to have included everyone in your strategic analysis except the Ukrainians. Take their position for a moment. The guy on their eastern border is behaving like a school yard bully. Hammering, invading and occupying smaller neighbors. He has been doing this and getting more and more aggressive all the time. He annihilates Georgia and Chechnya and then in 2014 attacks part of your country, Crimea, killing many innocents along the way and takes it over. You can see he’s a bad man with a lot more military might than you. So what do you do? You look for new friends to help you defend yourself from the bully. You gravitate toward the west because the guy to your east is an asshole. That is strategically smart.
The reason we are having this war is because no one wants to play with poor Vladimir and that pisses him off. The sooner he is separated from the air supply the better; for the whole world. Hopefully Ukraine survives long enough to see his ultimate demise.