What is our response when Putin Drops a Nuclear Weapon, strategic or conventional, in Ukraine

We can't believe that Putin is the kind of bully that hurts others without regard to the amount of harm he causes humanity and the kind of bully that doesn't back down when you stand up against him.  But, I think Putin has already shown us the type of bully he is ...  So you believe because the thought of nuclear weapons is so bad it couldn't happen ... therefore it won't.  But, it is not how you think that matters.