I'm calling it now...On the one hand he's smart enough to know that the outcome would not help him.
...Putin has such little respect for human life. ...Putin has such little tolerance to anyone dissenting against his authoritarian rule. ...Putin is in this for himself and doesn't actually give a shame about his country's citizen. ...Putin is so old he has nothing to live for if his rule is not absolute.
Putin will use his nukes.
On the other hand, his fragile ego might see it as preferable to being beaten.
I can imagine that China would start pushing hard if Putin started pushing nukes.