Putin has made it abundantly clear that under no circumstances will he give up Ukraine.

We have sat at the table repeatedly, but Putin has not stopped fighting.

As for "treaties", please recall that Putin signed a treaty with Ukraine promising never to invade it, in exchange for Ukraine's nuclear weapons.

Why would you possibly believe that Putin would respect treaties in future when he has not done so in the past?

You want to reward Putin for invading by giving him what he wanted, and you give no rational reason why this is a good idea. I'm baffled.