The European Union's missing voice: member states' forum shopping in military AI governance

This paper investigates why EU member states have largely opted for external forums, rather than the EU itself, to shape the emerging governance of military AI. While the EU's limited competence in security and defence is often cited as the primary constraint, its robust support for Ukraine following Russia's 2022 invasion or past involvement in other arms control forums challenge the idea that institutional limitations are insurmountable. Drawing on the concept of forum shopping, we introduce a two-dimensional analytical framework focused on institutional bindingness (ranging from soft principles to binding rules) and stakeholder engagement (from state-centric to transnational formats). We apply this framework to four key EU member states (Austria, France, Germany and the Netherlands) and assess their preferences across four institutional venues: the EU, the United Nations, the Political Declaration, and REAIM, covering the period 2019-2024. Our analysis reveals that, despite divergent policy preferences, these states converge around flexible, plurilateral forums that better match their strategic and procedural goals, leaving the EU marginalised not by default, but by design.