Quest for Coherence: European External Action Service’s Role in the External Dimension of EU Counterterrorism Policy

This article examines the evolution of interoperability within the European Union’s counterterrorism policy framework, arguing that recent developments represent a paradigmatic shift rather than incremental institutional change. Drawing on historical and constructivist institutionalism, we contrast the limited policy outcomes following the Madrid (2004) and London (2005) terrorist attacks with the ongoing implementation of a centralized EU interoperability framework since the Paris (2015) and Brussels (2016) attacks. Utilizing empirical data from EU documents and expert interviews, we identify cognitive reframing, strategic policy entrepreneurship, and positive feedback mechanisms as drivers of this transformation. Our findings suggest that while the interoperability agenda promises to enhance cross-border security coordination, it also raises critical concerns regarding data protection and purpose limitation. As such, interoperability illustrates both the potential and the tension of EU internal security integration: it offers functional gains in counterterrorism governance, but also reveals the normative and operational challenges of embedding supranational data infrastructures in a fragmented political and legal environment.