Various unknowns . Have to be guessed at so no total assurance can be given and this isn't going to go from thinking about a tactical nuke to superpowers firing ICBMS's at each in one step ... there'd need to be a few . There will be a disincentive provided by the US to extreme action by the US at each step .
The other question is at what point will Putin ceased to be obeyed by his military ? Would they tolerate MAD even if Putin did ?
The thing you haven't addressed is the issue of appeasement and the dangers there . Why would the ploy not be repeated if it worked once ?? I've asked this so many times and not sure that I've ever got ANY sort of answerr . ie. Whichever way you go , there is a degree of dange ... I don't think that can be denied .... just a matter of finding the best way .
