re:
So much could have been saved by fortifying Ukraine in advance with conventional weapons. Putin would not have invaded a well-equipped Ukraine --<
I doubt that. I think the main reason for Putin's invasion was that he didn't want a west-friendly country on his border. He didn't want them to join NATO. So as soon as the west started to significantly help this fortification, he would have invaded. And Ukraine was not capable of doing it on their own. And even if they did, and were showing success at it, he would invaded before it became a true obstacle.
I think the west was somewhat constrained in their options. They didn't want to provoke Putin, and worse didn't want to cause an invasion that might lead to direct battle. So their options were along the lines of telling Putin, "Don't invade. If you do, we will do this." You can decide whatever "this" should be, but that's the constraint. Putin believed he could win quick enough so that "this" would not have mattered. And he didn't believe the west would use nukes or any other significant weapons. So Putin's invasion was going to happen. I haven't heard a plausible scenario where it doesn't. Maybe an equally crazy man as Trump pledging to go nuclear on him and destroy the world if he does. But that's a bad bet to make, since the result of that is the end of human civilization if Putin dares him to do it.
I think we are still in the same spot. Putin is going to lose. And he can't let that happen. Which means he is going nuclear in some fashion. We keep saying, "Don't do it, or else the consequences will be severe." But what consequences can they promise that would actually dissuade him? Nothing that doesn't set us on the quick path to nuclear annihilation. I don't see any good answers then or now.
