The European Union and the Challenges of Terrorism: Threats, Responses and the Unresolved Balance between Collective Security and Fundamental Rights

Terrorism has been on the European Union's agenda for more than two decades, and in that time the problem has changed shape several times without ever going away. This paper asks what terrorism actually demands of the EU as a political system, and how far the Union has been able to meet that demand. It works through three questions: what the threat currently looks like, how the EU has organised its institutional response, and which tensions remain unresolved, above all the difficulty of pursuing collective security without eroding the fundamental rights the Union claims to protect. The study is qualitative and document-based. It draws on EU policy texts, the scholarly literature on the counter-terrorism strategy and its four pillars (Prevent, Protect, Pursue and Respond), Europol's most recent attack and arrest data, and Court of Justice case law, and it reads this material through securitisation theory. The review finds that instruments such as Europol, the European Arrest Warrant and Passenger Name Record (PNR) data-sharing have each been studied at length, but that three issues are rarely brought together: the trust deficit between national security services, the security–rights trade-off, and the growing share of attacks carried out by lone actors radicalised online. The paper argues that the EU's counter-terrorism system is a real institutional achievement but an incomplete one, and it closes with recommendations on trust-building between intelligence services, closer monitoring of national implementation, and rights-sensitive oversight of surveillance tools.