This is all fair, though you'd think a belligerent narcissist would be less likely to sacrifice themselves if it meant they might die, to be fair.
My point is simpler though: Tactical-operational and operational level weapon employment against solely military targets isn't going to trigger mass retaliation, and both belligerents might be willing to look past radiation in Shanghai or San Diego if it means the sole impact area is a military base.
This is different from the 1980's, except the very last few years or months of that decade, because the USSR had a pretty light hair trigger. It knew it wouldn't be able to necessarily "win" without attacking America directly, because America still controlled the financial and industrial wealth of the world, which is no longer the case today. This is why the USSR threatened to bring any tactical use of weapons to a strategic exchange, which shifted in the 1980's to the USSR thinking it might be able to constrain a tactical-operational use of weapons to the European theater solely, provided it avoided nuking any of the other P5's metropoles.
Similar thinking has captured DOD right now.
SLCM-N would fit in with GLCM and maybe some obscure Soviet nuclear cruise missiles as an airbase/radar/command post deleter. I don't think it's supposed to be used to vaporize apartment blocks or flatten CPC headquarters buildings, but perhaps I am wrong, and the U.S. is actually planning on moving its strategic deterrent to SSNs to augment the SSBN force.
It can do both, obviously, but the provisioning of fast attacks with nuclear weapons seems to be for operational concerns rather than strategic.
