The contentious status of the Durand Line between Afghanistan and Pakistan is a symbol of both the problems of state and nation-building and their conflict-prone relationship. First, the unresolved border of the Durand Line was a tool in the process of nation building by Afghan governments, whose demand until the 1970s for a “Greater Pashtunistan” challenged the territorial integrity of Pakistan. Second-ly, in the 1990s, the Durand Line acquired a regional dimension when the Pakistani military linked Afghanistan to its conflict with India over Kashmir. Finally, after 9/11 the Durand Line suddenly acquired a global dimension in the War on Terror. The solution for contested borders like the Durand Line does not lie in the continu-ation of confrontational policies as in the past, but in new strategies in order to foster cooperation. The pooling of sovereignty along the Durand Line was already being discussed in the 1930s and 1940s. Such concepts, which could include joint management of common cross-border issues, would be helpful in transforming the contested line into an area of cooperation rather than confrontation.