I might present an alternative plan for Ukraine: Much as I dislike the notion of negotiating with the likes of Putin at all, they could obtain a Russian withdrawal, following a serious beating of Russian forces, by pledging never to join NATO. And lie. They could then join NATO immediately the withdrawal was secured and rapidly receive symbolic NATO forces along their frontier with Russia.

This is essentially what Russia did with its pledge to ensure Ukraine's security in exchange for Ukraine giving up its nuclear weapons: It lied. I think it fitting to serve it as it has served.