There is also every reason to believe Putin is doing this to restore Russia to former size, influence and glory.

> Putin invaded in 2022 because he believed his hand had been forced. It wasn't, he was (and is) delusional and wrong, but there is every reason to think that he really believed it.

Then please name those reasons. As for the "negotiated settlement" you've brought forward - one could be forgiven to think that such a settlement would not be worth the paper it is written on: https://en.wikipedia.org/wiki/Budapest_Memorandum .