Title page 1

Contents 4

Disclaimers 2

Abstract 3

Executive summary 5

1. National security and implications for competition enforcement 6

1.1. The evolving scope of national security and long-term objectives 6

1.2. Competition and national security: Complementarities and tensions 8

1.3. How legal frameworks address national security in the context of competition enforcement 10

1.4. The role of competition authorities in an evolving national security context 14

1.4.1. The boundary of competition enforcement 14

1.4.2. Enforcement discretion, advocacy, guidance and institutional co-ordination 15

2. The analytical boundaries of competition enforcement in a national security context 17

2.1. National security as a constraint on competitors 17

2.2. Merger control 20

2.2.1. National security-related anticompetitive effects in mergers 20

2.2.2. National security arguments, justifications and efficiency claims in mergers 22

2.3. Co-ordinated conduct 23

2.4. Unilateral conduct 26

2.4.1. National security-related anticompetitive effects 26

2.4.2. National security arguments, justifications and efficiency claims 27

2.5. Remedy design 30

3. Conclusion 33

References 34

Notes 45

Boxes 4

Box 1. AI, competitiveness and national security policy frameworks 7

Box 2. National security derogations and exemptions from competition law 10

Box 3. Statutory exemptions and immunities for co-ordination in the public interest 11

Box 4. Public interest intervention mechanisms in merger control 12

Box 5. Competition advocacy and national security: exclusive rights in defence-related services 16

Box 6. National security and the assessment of credible competitive constraints: Siemens/Alstom 18

Box 7. National security restrictions and the set of feasible competitors: 5G infrastructure 18

Box 8. National security measures and competitive constraints: TikTok 19

Box 9. Foreclosure and access to critical inputs: NVIDIA/Arm 21

Box 10. Efficiencies and remedies in naval defence: Hanwha/DSME 22

Box 11. United Launch Alliance: National security, efficiencies and safeguards 24

Box 12. Authorised co-ordination in response to supply disruption: The Australian fuel sector 25

Box 13. Unilateral conduct in critical infrastructure and strategic sectors 26

Box 14. FTC v. Qualcomm: Unilateral conduct, innovation and national security 29

Box 15. Remedy design and national security: US v AT&T 30

Box 16. Remedy design and national security: EC's ENI commitment decision 31

Box 17. Remedy design, implementation and revision: CADE's Petrobras divestment remedy 31