Building on earlier RAND research that reviewed and integrated social science relevant to understanding terrorism and counterterrorism, this volume focuses on public support for both insurgency and terrorism and incorporates insights stimulated by social movement theory. The authors examine four case studies: al-Qa'ida’s transnational jihadist movement, the Taliban insurgency in Afghanistan, the Kurdistan Workers’ Party (PKK) in Turkey, and the Maoist insurgency in Nepal. The authors first developed a model, based on previous work, identifying the factors that influence public support for insurgency and terrorism and how these factors relate to each other. They then drew on extensive primary - and secondary-source material from each of the four case studies to evaluate and refine the model. Comparing the four case studies, the authors discuss which factors were most salient across cases and how their importance varied in each case. Finally, they offer a model of persuasive communications that connects the study’s research to issues of strategy and policy.