Border Walls as Cooperation Failures

Walls and barriers are defining features of contemporary border politics. While existing theories of walling emphasize economic and security threats as the principal cause of walling, we argue that this is better understood through a theoretical lens at the core of international relations: trust and mistrust between states. States benefit from cooperative border governance, but these strategies require trust to be maintained. Walling is a second-best option when a state cannot trust that their neighbor is willing or able to reciprocate cooperation. We find strong support for this argument after introducing a geo-located international border walls dataset. We show that walls are more likely to be constructed by hostile neighbors, who are unwilling to cooperate, and against incapable neighbors, who are unable. We then conduct a geo-spatial analysis of wall location, showing that rivals locate walls near potential security threats, while non-rivals appear more singularly motivated by economic concerns.