This chapter argues for the following definition of terrorism. Terrorism is a strategy that: 1. Consists in state or non-state actors deliberately performing acts of violence aimed at (directly or indirectly) seriously harming persons who are not military combatants, human rights violators or violent revolutionaries; 2. Consists of violent actions that ought to be criminalized; 3. Is an intended means of terrorizing the members of some social, economic, ethnic, political, etc., group in order to achieve a political purpose; 4. Relies on the violence receiving a degree of publicity, at least to the extent necessary to engender widespread fear in the target group.