Transverse Integration in EU CSDP Governance: The European Peace Facility in Ukraine, Niger, and with the African Union.

This paper examines how the European Union reacts to external security shocks and argues that, rather than moving along a linear path towards deeper defence integration, the EU increasingly operates through hybrid and adaptive forms of cooperation under the CFSP/CSDP framework. The European Peace Facility (EPF) provides an ideal lens through which to explore this dynamic. Across three distinct cases – Ukraine, Niger, and the African Union (AU) – the EPF has generated different but comparable patterns of governance that point to the transverse integration. Drawing on Dyson and Marcussen’s (2010) concept, the paper understands transverse integration as a dynamic equilibrium between unitary ambitions and differentiated realities. Rather than treating EU defence responses as evidence of either renewed cohesion or persistent fragmentation, the paper aims to explore how the EPF’s practice reflects governance marked by hybridity, multidimensionality, and continual dynamism. The EPF embodies the EU’s collective aspiration to act strategically; however, its implementation reveals cross-cutting coalitions, overlapping institutions, and variable participation that blur traditional insider–outsider boundaries. Methodologically, the paper employs interpretative content analysis of Council decisions, EPF financing documents and member-state statements, complemented where possible by interviews. This approach is used to trace how the three dimensions of transverse integration manifest across cases: crisis-driven hybridisation in Ukraine; arrangements in Niger; and institutionalised cooperation with the AU. Taken together, these cases suggest that the EPF does not advance a straightforward deepening of defence integration. Instead, it operates through transverse patterns of governance, making transverse integration a promising analytical lens for understanding contemporary EU CFSP/CSDP governance.