This chapter develops the main argument of the book. It posits that some displacement strategies – namely, forced relocation – act as a mechanism for sorting the population in wartime. The argument focuses on how the territorialization of political identity in civil wars and the tendency for combatants to utilize informational shortcuts impels them to use relocation to identify opponents through “guilt by location.” It also shows that relocation can create “zones of appropriation” that facilitate the mobilization of the population into the war effort, without requiring combatants to invest in resource-intensive methods of territorial occupation. To demonstrate the logic and plausibility of each aspect of the "assortative" theory of displacement and illustrate its central causal claims, the chapter provides empirical examples from a wide range of civil wars, from the Revolt of the Camisards in eighteenth-century France, to colonial wars in British, French, Japanese, and Portuguese territories, to modern conflicts in Angola, Bangladesh, El Salvador, Ethiopia, Guatemala, India, Nicaragua, Peru, the Philippines, Rwanda, and Sri Lanka. The chapter also discusses a set of hypotheses and observable implications of the theory.