In the last seventy years the nature of war has changed dramatically. Rather than involving two or more national armies fighting in uniform and obeying an orderly chain of command, most organised violence since the end of the Second World War has been asymmetrical, involving a regular army on the one hand and militia or guerrilla forces on the other.1 At the same time, the nature of battle – the intense, adrenaline-fueled close quarters confrontation that has traditionally defined the very heart of our idea of war (Keegan 1983) – is also changing as a result of dramatic advances in our ability to fight remotely. The increasing role of robotic devices and drones in recent conflicts, as well as the exponentially growing potency of cyberwarfare, are changing what it means to do combat. Now, asymmetrical war has been around forever. Defeated armies and weaker parties have often turned to guerrilla tactics against stronger foes. But, in recent decades, asymmetrical war has become the primary form of violence we encounter. Similarly, the history of military technology has always been the history of killing at a growing distance (swords allow more distance than fists, longbows than swords, rifles than longbows and so on). And yet, recent years have seen a qualitative leap in what we can do from far away.