Well, while obviously he may, I sense he wont. 2 reasons, one, Nato could use the nuclear fallout falling on a nato country as a trigger for article 5 and thats the end of Russia if not the whole world. Two, even if a nuclear response and article 5 trip does not happen, there would be a minimum of a Nato strike on every piece of equipment in Ukraine, and the sinking of the entire Black Sea fleet, per a guy more in the know than most of us.
https://thehill.com/homenews/sunday-talk-shows/3671100-petraeus-predicts-us-would-lead-nato-response-to-take-out-russian-forces-if-putin-uses-nuclear-weapon/
