Systematic killing has long been associated with some of the darkest episodes in human history. Increasingly, however, it is framed as a desirable outcome in war, particularly in the context of military AI and lethal autonomy. Autonomous weapons systems, defenders argue, will surpass humans not only militarily but also morally, enabling a more precise and dispassionate mode of violence, free of the emotion and uncertainty that too often weaken compliance with the rules and standards of war. We contest this framing. Drawing on the history of systematic killing, we argue that lethal autonomous weapons systems reproduce, and in some cases intensify, the moral challenges of the past. Autonomous violence incentivizes a moral devaluation of those targeted and erodes the moral agency of those who kill. Both outcomes imperil essential restraints on the use of military force.