The Diffusion of International Border Agreements

Abstract

Can actors’ interactions affect similar, future interactions between those initial actors and others? We investigate this broad question through the lens of international border agreements. In particular, we propose that border agreements can emerge through a previously overlooked mechanism: diffusion. Because border territory is salient, leaders are expected to misrepresent their positions and therefore have difficulty credibly conveying information to their counterpart. To overcome this problem, actors require a costly signal, and we argue that border agreements can serve this purpose. When a state signs a border agreement with a neighboring state, it signals to its other neighbors about both the existence of a bargaining range and the potentially acceptable provisions, thereby helping these other neighbors successfully conclude border agreements with the original signatory states. An analysis of all contiguous dyads during the period 1816–2001 uncovers substantial support for our argument.