Towards a common European culture on arms exports: a comparative constitutional law perspective.  Umberto’s research project examines the development of a common European culture on arms exports from a comparative constitutional law perspective, in light of recent geopolitical shifts. These changes have prompted renewed efforts toward increased defence cooperation among European states, particularly in the joint industrial development of weapons systems. However, such cooperation is hindered by the fragmentation of national legal regimes governing arms exports and their limited coordination. The project thus investigates the possibility of, and the conditions for, the emergence of a shared—albeit non harmonised—legal framework for the export of jointly developed arms, capable of both ensuring the respect of international legal obligations and allowing for the smooth cooperation among European states. While substantive rules across European countries show a high degree of convergence, largely due to international commitments, the institutional structures and procedures implementing these rules vary significantly. The central research question is whether the national frameworks regulating the export of arms can be considered functionally equivalent. This issue is crucial because procedural equivalence could justify systems based on mutual trust and recognition among states in joint arms export decisions, such as those that would result from the adoption of the proposed EU Defence Readiness Omnibus. Conversely, a lack of equivalence may require stronger safeguards, such as veto powers. The research therefore examines decision-making processes within national executives, the limited oversight roles of parliaments, and the judicial review of export decisions, particularly regarding the domestic application of international law. Methodologically, the project adopts a comparative constitutional approach, complemented by insights from international and EU law. It ultimately aims to propose a legal framework that balances effective European defence cooperation with strict adherence to international legal standards, contributing to both academic debate and policy development.