Border Walls, Refugees, and Terrorism

• In Event: Territory, Boundaries, and Governance

Abstract

Are physical walls between countries effective at reducing terrorist attacks? Despite their prohibitive cost and political divisiveness, walls between contiguous countries have recently proliferated as extreme forms of border control, especially following 9/11 and the 2015 refugee crisis. Yet, their effectiveness at mitigating the alleged refugees-terrorism nexus is largely unknown. We use the most updated dataset on walls between adjacent countries worldwide (1970-2016), and rely on the staggered construction of walls across some country-dyads over time as an identification strategy. Our findings reveal strong backfiring effects over time, whereby attacks substantially increase after the erection of a wall. Our difference-in-differences analyses and case studies of the walls between Saudi Arabia-Iraq (2014) and Israel-Egypt (2010) reveal two main mechanisms. First, out-group attitudes among both separated communities significantly deteriorate after the construction of the wall. Second, the opportunity to recruit and mobilize the aggrieved community increases as the refugee stock from contiguous countries hosting transnational terrorist organizations is larger. These findings have critical scholarly and policy implications by demonstrating the unintended consequences of highly restrictive border policies and showing how walls are not only ineffective against terrorism but may actually exacerbate the problem they intend to resolve.

Authors

• Sergi Pardos-Prado, University of Glasgow

• Sara Polo, University of Essex

• Julian Wucherpfennig, Hertie School