What makes terrorism modern? Terrorism, legitimacy, and the international system

This article aims to understand the phenomenon of international terrorism by wedding a constructivist understanding of terrorism with an overview of the historical evolution of the state. The Westphalian state has replaced three types of authority: religious, personal and local. Political challenges to the modern international system inevitably derive their claim to legitimacy from one of these other forms of authority. I argue that there is a correlation between the kind of legitimacy claim a 'terrorist' cause is based on and how threatening we find the activities based on that claim. The less the distance between the unrecognised legitimacy claim on the one hand and the principles conferring legitimacy in the modern states system on the other, the less ontologically threatening we find the claimants to be. All historical variants of modern 'terrorism' fall into one of two categories of disruptive activity. They are either based in claims to local authority and target only particular states, or in claims to personal and/or religious authority and reject the modern states system altogether. Groups labelled as terrorist can therefore be classified as system-affirming or system-threatening. The former is a contained problem, but the latter has followed geographically broadening spread pattern throughout the international system.