There are three basic premises of symbolic interactionism: human beings act toward things on the basis of the meanings that the things have for them; the meaning of such things derives from social interactions; and these meanings are managed in and modified through an interpretive process used by the person in dealing with the things he/she encounters. Five key symbolic interactionist concepts have been extrapolated from these three principles. This article applies them to the creation of a sense of identity in members of three terrorist groups: the Provisional Irish Republican Army, the Hamas, and the Tupamaros. After discussing a symbolic interactionist perspective of identity, the article provides an overview of the three terrorist organizations, followed by a discussion of identity and its relationship to the terrorist threat for each of the three terrorist organizations. The analysis provides a better understanding of how the terrorist identity is formed and is significant in motivating terrorist behavior. This can be useful for law enforcement personnel in profiling, tracking, detecting, and apprehending those accused of committing terrorist acts. For policymakers, understanding the power of a sense of identity explains why terrorist behavior persists and adapts in the face of apparently insurmountable obstacles and changing conditions. Also, using violence and other punitive measures against them may confirm their identity and commitment to conflict, fueling their motivation and confirming an ideology of violent struggle that is the essence of their identity. 102 references