This report provides a practical tool–a guidebook and a methodology to follow–to help intelligence analysts determine the long-term potential for communitarian and ethnic conflict. It is based on a conceptual model of group conflict. The three-stage model traces the development of ethnic and communitarian strife, beginning with the conditions that may lead to the formation of an ethnic group, then the group’s mobilization for political action, and ultimately its competition with the state. The main body of the handbook is formatted as a series of questions and guidelines for the analyst to consider while preparing an assessment. An appendix provides a full theoretical explanation of the model. As its goal is to provide a tool to help intelligence analysts predict whether a competition between an ethnic group and the state will end in violence, the model supplies a series of matrices to help identify the conditions that may lead to ethnic and communitarian strife.