The purpose of this study is to focus attention on the types of individuals and groups that are prone to terrorism in an effort to help improve U.S. counterterrorist methods and policies. The emergence of amorphous and largely unknown terrorist individuals and groups operating independently and the new recruitment patters of some groups, such as recruiting suicide commandos, female and child terrorists, and scientists capable of developing weapons of mass destruction, provide a measure of urgency to increasing our understanding of the psychological and sociological dynamics of terrorist groups and individuals. The approach used in this study is twofold. First, the study examines the relevant literature and assesses the current knowledge of the subject. Second, the study seeks to develop psychological and sociological profiles of foreign terrorist individuals and selected groups to use as case studies in assessing trends, motivations, likely behavior, and actions that might deter such behavior, as well as reveal vulnerabilities that would aid in combating terrorist groups and individuals.