Is there a duty to prosecute grave international crimes? Many have thought so, even if they recognize the obligation to be defeasible. However, the theoretical literature frequently leaves the grounds for such a duty inadequately specified, or unsystematically amalgamated, leaving it unclear which considerations should drive and shape processes of criminal accountability. Further, the circumstance leaves calls to end impunity vulnerable to skeptical worries concerning the risks and costs of punishing perpetrators. I argue that a qualified duty to prosecute can (...) be substantiated on the basis of a single class of reasons, though also that standard justifications of international criminal law (as currently conceived) are not up to the task. The account exploits the expressive dimension of punishment, but locates the central good of criminal accountability in its capacity to appropriately enable an agential stance on the part of subjects in transitional circumstances. It can legitimate, in a way to be specified, hope. The approach also displays the cynicism of an anti‐impunity ethos in the absence of a robust commitment to securing basic human rights in transitional circumstances. (shrink)