Do Walls Work? The Effectiveness of Border Barriers in Containing the Cross-Border Spread of Violent Militancy

Abstract

Since the end of the Cold War, walls, fences, and fortifications have been constructed on interstate borders at a rapid rate. It remains unclear, however, whether these fortifications provide effective security. We explore whether border fortifications provide security against the international spread of violent militancy. Although barriers can reduce the likelihood that militant activity diffuses across international borders, their effectiveness is conditional upon the roughness of the terrain on which they are built and the level of infrastructure development in their proximity. Barriers require intensive manpower to monitor and patrol, and so conditions like rough terrain and poor infrastructure render security activity more difficult. However, rebels and other militants prefer to operate in such difficult areas, ultimately reducing the effectiveness of barriers in containing the international spread of violent militancy. Analyses on newly collated data on interstate border fortifications within a global sample of contiguous-state directed-dyad-years show that border fortifications are only effective in limiting the diffusion of militancy in contexts in which states can plausibly monitor and police their borders. This paper has significant implications for the academic literatures on national security and intrastate conflict, and it also speaks to the broader policy debate over border walls and fences.

Changes in perceptions of border security influence desired levels of immigration

“…For example, while there is evidence showing that border barriers can substantially reduce terrorist attacks when they are monitored by law enforcement agents (Avdan and Gelpi, 2016;Linebarger and Braithwaite, 2020), there is also evidence suggesting that they could radicalize the target population (Longo, Canetti, and Hite-Rubin, 2014;Gade, 2020). And whereas border walls decrease crime and smuggling in protected towns, they also turn not-protected towns to the new target of smugglers (Getmansky, Grossman, and Wright, 2019).…”

“…One widely held view in the literature is that borders facilitate divisions between insiders and outsiders, "us" and "them" (Longo, 2017;Mendez and Naples, 2014). Another view is that border security measures are usually counterproductive: i.e., they rarely meet their goals, be it curtailing immigration or countering terrorist attacks, and they have very little material benefits but significant ramifications to the nations that build them (Longo, Canetti, and Hite-Rubin, 2014;Carter and Poast, 2019;Schon and Leblang, 2021;Linebarger and Braithwaite, 2020). 2…”

Why Physical Barriers Backfire: How Immigration Enforcement Deters Return and Increases Asylum Applications

“…We include our first instrument, Logged Land Boundary Length , based on the notion that longer boundaries may increase government desire to build barriers. Long boundaries may be difficult to manage, so barriers could help governments focus their resources on a smaller area (Avdan & Gelpi, 2016; Linebarger & Braithwaite, 2020).…”

Walls and Strategic Innovation in Violent Conflict

“…Yet, our theoretical argument on the effects of walls generalizes beyond this single case. Existing research suggests that walls effectively prevent the spread of militancy where conditions allow the government to monitor and maintain the barrier (Linebarger and Braithwaite 2020). Israel’s barrier cuts across desert easily traversed by off-road vehicles and certainly meets this condition, as do many of the other counterterrorism barriers mentioned above.…”