A simple model of Putin and the Ukraine crisis

I think the correct model here is “Putin has put down so many chips, he can’t walk away with nothing. He wants to wreck Ukraine (more than taking territory per se).  He will do the minimum amount he can that leaves him with a strong probability of having wrecked Ukraine, and no more.”

That still leaves a broad range of possible outcomes, but at the moment that is my mental model for updating with new information.