This paper examines how the European Union governs preventive counterterrorism (also known as counter-radicalisation) through indirect means. It explores how the EU enlists local actors (teachers, youth workers, NGOs, municipal officials) to implement its prevention policies, despite national security formally remaining a Member State competence. Based on interviews with practitioners from across Europe, the paper shows how EU influence expands through funding, training, and knowledge networks like the Radicalisation Awareness Network (RAN).