This article suggests that understanding the unspoken assumptions of nuclear weapons policy depends on understanding late-19th-century literary accounts of superweapons, which prefigured the atom bomb. Such accounts were utopian. They envisioned world peace brought about through a technological breakthrough, one that would allow a single nation to achieve absolute hegemony. This article demonstrates the links between ‘future war’ stories written by authors such as Jack London, Frank Stockton, and Roy Norton, on the one hand, and the nuclear deter- rence reasoning of US leaders such as Harry Truman, Richard Nixon, and Donald Trump, on the other. The nuclear device realises the dream of a technology suited to coercive diplomacy and little else, and as a result it traps 21st-century nation-states in a set of relations devised by thinkers in the 19th century. This article suggests, ultim- ately, that the danger of reverting to the logic of 19th-century coercive diplomacy will remain as long as nuclear weapons do.