It does not seem likely to me that Putin would use a nuke offensively. The most likely scenario for actual deployment is in a mutually assured destruction scenario by the side that is losing and being threatened with total annihilation. Putin would have a hot war with all of NATO if he deployed a nuke, theres no way he does this while he is winning. Mostly nuclear weapons are just used for this kind of propaganda brinksmanship, this sounds eerily similar to 'Iraq has weapons of mass destruction and yellowcake uranium' and we need to get them before they get us