Why do combatants intentionally uproot civilians? The forcible relocation of families and communities to concentration camps, "protected villages," and other special settlements is a regular feature of irregular war, occurring in almost a third of all counterinsurgency campaigns since 1816. Despite the historical regularity of these practices, most research has focused on individual decisions to flee, rather than the brute-force resettlement of civilians by combatants. Using a dynamic model of popular support and new micro-level data from Soviet secret police archives, I show that civilian resettlement is not simply a by-product of war but is a rational response to informational asymmetry. Combatants who cannot identify and selectively punish their opponents face incentives to control the population rather than earn its support. For strong governments with limited coercive leverage, civilian resettlement offers a way to reduce rebel activity without having to win hearts and minds.