In recent years, a growing literature has argued that European Union (EU) member states have undergone a profound transformation caused by international institutions and by the EU, in particular. However, the state core – the monopoly of the legitimate use of physical force, embodied by the police – seemed to remain intact. The literature has argued that in this area, international institutions are weak, and cooperation has remained informal and intergovernmental. We take issue with these claims and evaluate the strength of international institutions in two core areas of policing (terrorism and drugs) over time. We find that in terms of decision-making, precision, and adjudication, international institutions have become considerably stronger over time. Even when international institutions remain intergovernmental they strongly regulate how EU member states exercise their monopoly of force. Member states are even further constrained because adjudication is delegated to the European Court of Justice. Thus, even the state core is undergoing a significant transformation.