The international regulation of terrorism has invariably confronted two major challenges. First, as nonstate actors, most terrorists have no clear standing under international law. Second, because terrorism is inherently political, it invariably provokes varied responses from states. This chapter shows how states have coped with these two challenges and how they have reframed the struggle to suppress terrorism using diverse legal structures and principles. In particular, it shows that the scope of what could be termed “justifiable” terrorism has narrowed dramatically, especially over the last decade, and the scope of justifiable responses has broadened proportionally. At the same time, the status of terrorist groups has changed in fits and starts over the years as states seek greater control over what may well be uncontrollable.
Keywords: international law, international norms, justifiable terrorism, justifiable response, terrorist,