This chapter defines terrorism as the 'use or threat of violence to achieve a social, political, or religious aim in a way that does not obey the traditional rules of war.' Although many terrorists, especially terrorist leaders, are mentally healthy, adaptive, and highly motivated, individuals with severe psychopathology may be used in various terrorist incidents. Although many terrorist behaviors appear to the outsider to reflect individual psychopathology, the behaviors are normative for the socially isolated small groups of which they are a part. Terrorist incidents which occur over a significant time period manifest various psychological dynamics, among them being the Stockholm syndrome, which is a positive attachment between hostages and hostagetakers. Adult survivors of terrorist incidents must face several difficult psychological tasks. First, they must resolve their feelings about their own behavior under stress. Second, they must resume control over their own lives; and third, they must re-establish belief in the predictability of daily life and the trustworthiness of others. Regarding the clinician's role, primary intervention includes the psychological preparation of high-risk populations and the larger community for terrorist incidents. Secondary intervention includes crisis intervention with victims, their families, and the affected community. Tertiary intervention involves the long-term treatment of posttraumatic stress disorders and other psychological after-effects. 24 references.