I believe it was purely for reasons of expansion. I don’t know exactly what our response should have been, but we need to at least acknowledge that Ukraine is defending their sovereignty and Putin/Russia are the aggressors. We should support them at least minimally.
It is my understanding that Ukraine has been willing to talk about peace but not willing to give up any part of their country. Giving in to a demand like that seems like giving the mugger exactly what they wanted. IDK. What does Russia really have to negotiate with other than taking some of Ukraine’s freedom?