Sailorsaint,
Much respect but I'm not getting into a what if game. What Ukraine and Russia agree to and whether the peace deal is lasting or fair or whatever is irrelevant at this time. IMO the fighting needs to stop, and the parties (Ukraine and Russia) need to start meaningful discussions. Trust this party don't trust that party what are you going to do? You have to try to negotiate a peace with him. I get it, Putin is evil. But he and Zelenskyy are the only two people who can make the fighting stop. So, you have to try regardless of all the if's and but's.
On appeasement, history isn't kind on that point. The West basically rolled over after the first invasion so your point on history repeating is well taken. Still doesn't mean you don't reach for peace, IMO.