Ontological and epistemological challenges of measuring the effectiveness of urban counterterrorism measures

Cities and their citizens are increasingly seen as vulnerable targets for terrorist attacks, and nowadays city planners have become important actors in making decisions about urban security. Multiple urban counterterrorism measures that have affected the urban landscape have been implemented in recent years. Simultaneously, new legislation requires security measures to be effective. This article outlines and discusses the epistemological and ontological challenges of acquiring knowledge about the effectiveness of urban counterterrorism measures from a local city planner’s perspective. This piece of work is a discussion paper based on a literature review. We conclude that, despite the knowledge limitations regarding the threat of urban terrorism and associated countermeasures, local planners should refrain from just uncritically implementing urban countermeasures without considering the effectiveness of such measures. Without knowledge on what constitutes the effectiveness of urban security measures, the city might end up infringing the same values that it aims to protect, without achieving security