The EU’s Mutual Defence Clause: Legal and Strategic Considerations on Article 42(7) TEU in an Age of Renewed Military Threats

A legal and strategic analysis of the EU’s mutual defence clause, Article 42(7) TEU, which echoes NATO’s Article 5 but has drawn little scholarly attention. Examining its interplay with the EU’s solidarity clause and NATO’s own mutual defence commitment amid the war in Ukraine, the paper concludes the EU cannot yet credibly threaten force in collective defence. (DELI Working Paper No.4/2025)