Zim, another option would be for Ukraine to acknowledge the captured lands as lost PROVIDED they become independent, neutral, border states - not part of Russia.
Why would Russia maybe agree to this? Tthat is where the concessions and creative negotiations come in.
I think an economic/trading alliance between the US and Russia would benefit both countries enormously. And, as I already said, it would put a substantial damper on Chinese expansion. (which would be a huge benefit to the US and to the world).
What do you think of that?