Criminalized power structures (CPS) are illicit networks that profit from transactions in black markets and from criminalized state institutions while perpetuating a culture of impunity. The book articulates a typology for assessing the threats of CPS and for implementing appropriate strategies to achieve sustainable peace effectively and efficiently. The international case studies address interventions undertaken either to support the implementation of a peace agreement (i.e., a peace operation) or to stabilize a country entangled in an internal conflict in the context of a power-sharing agreement among key protagonists (i.e., a stability operation). In each of these cases, at least one of the parties to the agreement was a criminalized power structure that was a leading spoiler. The final chapter identifies strategies that are most effective for each type of CPS, including the ways and means (or tools) required for effective conflict transformation. A companion volume, Combating Criminalized Power Structures: A Toolkit, provides practitioners with the means of coping with the challenges posed by CPS.