No government is ever going to shoot a nuke first. There is no scenario for that. Only an act of terrorism or an accident will a nuke be launched/detonated. And since that type of launch or detonation will be a singleton it will be apparent it is not a general nuclear strike.
Are you one of the ones who thinks Russia would accept a conventional attack and not pop nukes? Our Generals think they would.
In the cold war NOBODY expected them to come through the Fulda Gap and for it not to go nuclear.