megadeath is not the only thing that makes the Doomsday Machine petrifying. The real terror is in its autonomy, this idea that it would be programmed to detect a series of environmental inputs, then to act, without human interference. “There is no chance of human intervention, control, and final decision,” wrote the military strategist Herman Kahn in his 1960 book, On Thermonuclear War, which laid out the hypothetical for a Doomsday Machine. The concept was to render nuclear war unwinnable, and therefore unthinkable.