Russia holds all the cards.
Why would they fold?
Because they are in an endless war that they can't get out of and which is draining their economy?
I really don't think that Russia anticipated this being the situation three years ago. I suspect that there are many on their side that are hoping for an end to the war that saves face for Russia.
There is a deal to be made.
Traditionally such negotiations begin with each side offering a wrapped gift to the other side as a show of friendship.
I think Putin would be very pleased with Z’s head in a box.
Because Russia thought they could take Ukraine in a month. Yet here we are..