Do you not believe that an enemy with tactical nukes that faced an existential threat from CBGs would use them?
I've believed this since various REFORGER exercises presumed air cover from CBGs. The Russians would NEVER allow themselves to be defeated if it could be prevented by tactical nukes at sea - and no President could or would release strategic weapons in response to an attack that killed zero US civilians.
“Do you not believe that an enemy with tactical nukes that faced an existential threat from CBGs would use them?”
I believe anything is possible. I also believe that if we are ever in that situation, something probably happened in the world where global nuclear war is inevitable. If an enemy is ready to launch a nuke, everyone will want in.