Unlike wars between states and civil wars, tribal wars are fought between village communities that are either not controlled by or no longer under the authority of a central government. Through examples from New Guinea, the Amazon, and East Africa, Jürg Helbling examines the patterns and causes of these wars. Is war caused by innate human aggressiveness, cultural factors, or upbringing? Is it driven by competition for scarce resources, or are wars instigated by politically ambitious leaders? Helbling develops an alternative theory of tribal warfare, inspired by theories of international relations and game theory.