This volume affirms the widely shared view that global security now hinges on the ability of the international community to strengthen weak and failing states. Exploring the causes and consequences of state weakness in the developing world, these experts focus on "poorly performing states" -- those that exhibit the bleakest features of poverty and deficient government and are thus most prone to collapse. They argue that these troubled states all too easily become sites for illicit transnational networks and regionally destabilizing violence but are largely neglected by U.S. aid programs, such as the Millennium Challenge Account, which direct funds to "best performers." Corruption and state-sponsored predation are inevitably part of the story of state failure, but, the authors argue, the international community has also played a role in "supporting, emboldening, and replicating" ineffective government in weak and failing states. In a useful chapter, Carol Lancaster presents a set of principles to guide U.S. foreign assistance, emphasizing a case-by-case approach and utilization of the full array of carrots and sticks. But altogether, the authors underscore what is already known: the leverage of the outside aid community is limited and, without the presence of reform-minded elites, almost nonexistent.