I can’t immediately find a reference for this, but I would assume that all US forces deployed to support NATO in Europe can be commanded by the Supreme Allied Commander (SACEUR) who is always an American general. If the Russkies decide to invade, I’m sure that SACEUR has the authority to dictate response if he can’t immediately reach the President.
The only reason that NATO would need to urgently and immediately speak to POTUS is for nuclear weapons release, and fortunately that scenario has been wargamed to hell and back.
Jeebus louiebus.
The union voted internally on a resolution, and then union leadership held a press conference following that resolution? What else is the guy supposed to do, but represent the will of his constituents?