Towards EU(ropean) Differentiated Defence Integration?

Russia’s war against Ukraine and growing uncertainty about transatlantic security guarantees have reinforced the EU’s role as a security and defence actor. In recent years, we have seen a rapid development of mechanisms both at the EU -level and the member state level. At the EU level, mechanisms, such as Permanent Structured Cooperation (PESCO), the European Defence Fund (EDF) as well as temporary measures such to ensure rapid deliveries to Ukraine of weapons and ammunition, have been established. Going forward, it is likely that the EDF and the various temporary mechanisms will be integrated into the new European Competitiveness Fund (ECF), which brings together multiple financing instruments to strengthen Europe’s strategic capacities across defence, space, industry, technology, and civil security. In addition to these mechanisms, there are also initiatives, such as coalitions of the willing or various forms of minilateral cooperation formats that include both members and non-members. These recent development highlights that European security defence integration increasingly takes place through differentiated integration (DI), where coalitions of willing states – both inside and outside the EU – drive processes forward. This contribution argues that DI, including external formats that enable participation by non-member states such as Norway and the United Kingdom, does not necessarily undermine European unity. On the contrary, this flexibility can strengthen Europe’s overall capacity to act, build resilience against both military and hybrid threats, and at the same time balance considerations of legitimacy and inclusiveness in the emerging defence architecture.