Abstract

While terrorism is a practice, it is also a doctrine, and as such has abstract underpinnings reflecting a theory about its presumed effectiveness. Terrorists, however, are not the only ones who have theories of terrorism. Counter-terrorists and academic scholars who reflect on the origins, workings and outcomes of terrorist campaigns also have their own theories. With the proliferation of explanations about terrorism, the body of theories has grown considerably since the 1980s, when Schmid first summarized existing theories. ¹ In the following, we shall try to offer a new compendium of theories of terrorism. Before doing so, let us look at what constitutes a theory. Theory, to begin with, is, in the social scientific sense, a heuristic procedure used to determine broad lines of cause–effect relationships. It is, in effect, a simplification of reality that illustrates the dynamics of a relationship with certain inputs and outcomes. More often than not, we do not have fully fledged theories, only some empirical generalizations that are the lowest form of theory.