An appeasement-style solution like this is predicated on the assumption that the expansion of NATO is the actual reason behind this war, and not just a convenie

An appeasement-style solution like this is predicated on the assumption that the expansion of NATO is the actual reason behind this war, and not just a convenient pretext. There's no consensus about that. Putin has a history of meddling in neighbouring states, and could use a distraction from domestic problems.