This Is the Way the World Ends by James Morrow
When tombstone engraver George Paxman is offered a bargain, he doesn't hesitate. His beloved daughter gets an otherwise unaffordable survival suit to protect her from radioactive fall-out and all George has to do is sign a document admitting that, as a passive citizen who did nothing to stop it, he has a degree of guilt for any nuclear war that breaks out. George signs on the dotted line. And then the unthinkable happens.
The world and everyone in it (survival suit or not) is destroyed in a nuclear Armageddon - except for George and five others who must now face prosecution from the great mass of humanity who will now never be born. And George Paxman stands accused in the name of all the people who stood by and never raised a finger to stop the horror of nuclear war ...