C. J. Chivers’s extraordinary new book tells an alternative history of the world as seen through these terrible weapons. He traces them back to their origins in the early experiments of Gatling and Maxim, and examines the first appearance of the machine-gun – a weapon that first created the ‘asymmetric’ colonial massacres enjoyed by the British in Africa but which then created the nightmarish stalemate of the First World War. The quest for ever greater firepower and mobility culminated in the AK-47 at the beginning of the Cold War, designed by a Red Army tank commander and poet; a weapon so remarkable that, over sixty years after its invention and having broken free of all state control, it has become central to civil wars all over the world. The machine-gun reused many innovations associated with the new agricultural technology of its time (as did the tank), and there is perhaps no better example of how so much of the modern era has turned on the awful ambiguity at the heart of human inventiveness.