I ready a story once that had the Soviets launch 20 ICBMs at the US and Europe, which were aimed at destroying our retaliation capability and at Washington (or some other major city). As they launched, they announced the attack and claimed that if we did not respond, that would be the end, but that if we did, then they’d fire the complete arsenal and effectively bring about the end of civilization. I think they mentioned that they’d done the analysis to say that their attack was carefully calculated to prevent nuclear winter, but that further detonations from a counter attack would send us over the brink. It was basically a “what if” that wondered what the US would do when faced with such a threat.
At this point, I wonder if Russia is moving in this direction. I mean, if they invaded Poland, what would we really do if they said, “leave us be or we nuke your top ten cities”?
If I were in charge, I would propose negotiations, start evacuating our cities and then erase Russia for good.
If that blackmail were allowed to work once, it would never end.