The Making of the Territorial Order: New Borders and the Emergence of Interstate Conflict

We argue that new international borders are rarely new. We propose that when states choose new borders they use previous administrative frontiers to solve a difficult short-term bargaining problem and a long-term coordination problem. With a unique new set of data collected specifically for this project, we systematically examine the new international borders of the twentieth century resulting from secession, partition, and the use of force. New international borders, we find, are drawn not according to principles of "nationalism" or defensible borders, but rather according to previous administrative frontiers. How borders are drawn has important consequences for international stability: borders drawn along previously existing internal or external administrative frontiers experience fewer future territorial disputes and have a much lower risk of militarized confrontation if a dispute emerges.