Speculating about doomsday scenarios can provide a paradoxical comfort. "Scenarios can sometimes prove eerie for their resonance with the real world. In Hackett's book, once the military front in Europe settles into stalemate hard-liners in the Kremlin make the decision to destroy a single British city with a nuclear-tipped missile. It is a warning: come to terms now, or risk the fate of the world. Forty years later, this gruesome calculus is what nuclear planners refer to as 'escalate-to-deescalate.'" Matthew Kirschenbaum contemplates.