The question of how to constrain states that commit severe abuses against their own citizens is as persistent as it is vexing. States are imperfect political forms that in theory possess both a monopoly on coercive power and final jurisdictional authority over their territory. These twin elements of sovereignty and authority can be used by state leaders and political representatives in ways that stray significantly from the interests of citizens. In the most extreme cases, when citizens become inconvenient obstacles in the pursuit of the self-serving ambitions of their leaders, state power...