In recent years the efforts to hold the perpetrators of mass atrocities accountable have become increasingly normalized, and building capacity in this area has become central to the strategies of numerous advocacy groups, international organizations, and governments engaged in rebuilding and reconstructing states. The indictment of sitting heads of state and rebel leaders engaged in ongoing conflicts, however, has been more exceptional than normal, but is nonetheless radically altering how we think about, debate, and practice justice. While a principled commitment continues to underpin advocacy for justice, several court documents and high-profile reports by leading advocacy organizations stress the capacity of international justice to deliver peace, the rule of law, and stability to transitional states. Such an approach presents a stark contrast to rationales for prosecution that claim that there is a moral obligation or a legal duty to prosecute the perpetrators of genocide, crimes against humanity, and war crimes. Instead, recent arguments have emphasized the instrumental purposes of justice, essentially recasting justice as a tool of peacebuilding and encouraging proponents and critics alike to evaluate justice on the basis of its effects. Rationales that stress the results that international justice can help deliver have raised the expectations of proponents and skeptics alike and also encouraged further empirical study of the effects of justice. While these studies may not produce a consensus, they offer the prospect that justice strategies can be adapted based on careful research to be more effective. A focus on pragmatism does not mean abandoning the principled commitment to international justice, but it may mean deferring justice until conflict is resolved.