Substrate

Organised violence tends to appear where the substrate makes it the higher-return move, and to recede where it does not. That is one way to read the origins of war. Inverted, the same reading yields a second claim, less obvious and more useful. If war is what the ground rewards under some conditions, then peace is what the ground rewards under others, and neither is the default. A long stretch without organised violence is not the absence of something. It is the presence of conditions under which cooperation pays, and conditions like that can be built, and they can wear out. ...

Humans have probably always killed one another. Warfare is something narrower. It implies groups, planning, logistics, memory, leadership, and enough social organisation that violence stops being a personal act and becomes a collective institution. The interesting question is not when humans first killed. It is when killing acquired administration. Ask that question and a small crowd of theories turns up, each with its own literature, its own favourite dig site, and its own conviction that the others have missed the point. The Hobbesians say war is ancient. The Rousseauians say civilisation invented it. The circumscription theorists say geography did. The economists point at surplus, the anthropologists at prestige, the international relations scholars at the security dilemma. Each theory has evidence. Each has counterexamples. The usual response is to pick a champion and treat the rest as noise. ...