The problem with your analysis is that Putin is not reasonable. He has imperialistic ambitions that can only be thwarted by containing him. Ukraine has every right to ask that Russia withdraw from its territory including Crimea. Ukraine has never been a threat to Russia. The reverse cannot be said as evidenced by the brutal invasion that Putin has conducted. Would you want to live in an annexed part of Ukraine under Russian hegemony? I wouldn’t. You can only negotiate with someone who’s willing to be reasonable. The starting point is that Putin must agree to withdraw from all conquered territories. There is nothing to negotiate until he is willing to do this. But then of course, Putin is not rational, nor reasonable. If you allow him to get away with nuclear blackmail, it will just embolden all the other autocrats around the world who have nuclear weapons and territorial ambitions of their own. The international political arena will quickly spin out of control. Your speaking out of your own self interest, not by considering the bigger picture.