For the purposes of this article, war may be defined as organized and coherent violence conducted between established and internally cohesive rival groups. In contrast to numerous other modes of violence, it is neither individual, spontaneous, random, nor irrational, however much—like all varieties of violence—it involves destructive action, even on a massive scale. Being a complex phenomenon, war has multiple dimensions that are deeply interrelated, chief among them being economic, ideological, and social factors.

Of these, perhaps the most obvious and important (at least according to the majority of modern analysts) are the economic factors that precipitate war, war being the most extreme form of competition for chronically scarce resources, such as women, territory, movable wealth (including livestock), and/or the labor power of subjugated populations. One must note, however, that scarce and valued resources are not exclusively of a material nature, prestige being...