It's important to distinguish that there is also a variety of ways in which Putin could use a nuke, which in itself would have different scale of consequences. If he uses a tactical nuke outside of a major city, that is going to garner a different response from the West compared to if he obliterates Kyiv. I actually think that short of a full-on nuclear assault, NATO isn't going to escalate beyond the current protocol of sending better weapons to Ukraine. I worry about Putin's calculus on that front.Speculation. You don't know what they will do. I don't know it. We've never been in such a situation before. There will undoubtedly be a response, but whether any "western" government is ready to risk a nuclear war with Russia is doubtful, and it is possible that this is what Putin is or will be banking on.