I see three ways for this war to end. One, Ukraine will exhaust its forces and supply of weapons, but will not defeat Putin. At that point, it will concede the loss of some or all of its territory.
Two, Putin will exhaust his conventional forces, but will not concede defeat. He will use his tactical nuclear weapons. To avert all out nuclear war, Ukraine, and the West, will concede defeat.
Three, Putin uses his tactical nuclear weapons and all-out nuclear war unfolds.
I’m betting on option two. But if that’s the way this plays out, we have a lot of thinking to do. We cannot simply concede whatever demands Putin puts forth in the future, or can we? Having invented these horrid weapons, must we now give up all that we believe in to prevent their use? We’ve been creeping toward this fork in the road even since Hiroshima and Nagasaki. IMHO.