Among the first durable political borders were the Roman limites – built of stone or marked by ditches, or fortifications – at the Empire’s frontiers in North Africa, Germany and Britain. But a border has always meant more than a wall, fence or line; Derrida, for one, writes of the epistemological charm of borders, as expressions of our innate cravings for distinctions and certainty, for comfort and security.
For many in international affairs, borders are material facts, dividing the world into what John Ruggie calls “fixed, disjoint and mutually exclusive territorial formations.” On this view, borders may be “contentious and controversial in their location” (as John Williams argues in his 2006 book The Ethics of Territorial Borders) but not in the function they perform.