Putin will not go nuclear. There’s nothing for Russia to gain by using nukes on a Ukrainian city and given that a lot of Russians are from Ukraine and fond of it he’ll irreversibly alienate these people for life.
Putin through one of his lackeys floated the idea of firing a Russian nuke at the United States Nevada test range to prove some absurd point. The US simply restated our long standing policy that we do not believe in limited nuclear war. Any nuclear attack on the US will result in a full retaliatory attack on Russia.
It would be national suicide for Putin to give the nuclear order and I doubt his generals love him so much that they’d kill their country in order to demonstrate their loyalty to a madman.
But I do not believe Putin to be a madman. Just a sociopath.
So stop worrying about WMD. It’s highly unlikely. It would also be bad for business.