Nothing has changed except Putin regrets his decision to invade Ukraine more and more each day because he now sees in it his own demise and ruination of ruZzia which was 100% avoidable. Nuclear is not an offensive option because nuclear defense exists so it’s of no advantage. In fact depending on Western defenses, a nuclear option could simply be ruZzia committing suicide for no reason. The only advantage available is withdrawal because they can repent and resume commerce and lick their wounds in a better post Putin ruZzia. But it will take decades to recover from his Imperial fantasy fiasco.