Assessing border walls’ varied impacts on terrorist group diffusion

Do border walls inhibit the spread of transnational terrorism? Previous research has primarily measured the volume of terrorism without explicitly modeling its diffusion or considering how walls might affect different groups differently. To address these oversights, the study adopts a network-based approach, analyzing the impact of border walls on the spread of violence among 63 extremist organizations from 1970 to 2017. The findings show that barriers generally inhibit diffusion, but their effectiveness varies significantly among groups. This research challenges policymakers who regard walls as a catch-all solution for terrorism, offering a fresh perspective on whether walls’ effects justify their cost.