National security considerations in competition enforcement

National security considerations are becoming increasingly prominent in economic policymaking, reflecting geopolitical developments, technological change and growing attention to economic security, resilience and technological capability. As these considerations extend beyond traditional defence-related domains, they are intersecting more frequently with competition enforcement across a widening range of sectors, such as energy, telecommunications and advanced technologies. This paper examines the implications for competition authorities. It develops an analytical framework to distinguish between concerns that can be assessed using established competition law tools, where they can be expressed as competition-relevant effects, and those that fall outside the analytical remit of competition authorities and require assessment by governments or specialised bodies. Drawing on cross-jurisdictional experience, the paper analyses how national security considerations arise in the assessment of competitive constraints, merger control, co-ordinated conduct, unilateral conduct and remedy design. It identifies key considerations for preserving analytical boundaries, institutional roles, legal predictability and effective enforcement in an evolving policy environment.