Guardians of Western Order: Informal groups and European Security after Ukraine

The proliferation of informal groups in response to the war in Ukraine has been widely portrayed as a novel feature of European security politics. Some scholars interpret these formations as evidence of institutional erosion, reflecting ad hoc, minilateral arrangements that bypass formal structures, while others view them as federalizing engines, fostering deeper integration and cooperation within the EU. By conceptualizing informal coalitions as hybrid spaces situated between ad hoc transatlantic cooperation and formal EU governance, this article intends to consider a largely overlooked aspect in existing scholarly literature: the role of third states in these arrangements. It argues that informal groups typically serve dual functions. Within the EU, they facilitate consensus-building among member states, smoothing decision-making and enabling resource-pooling. Outside the EU, they support coordinated international responses to high-profile security and political challenges, often through the alignment of member states’ interests with those of the US as the hegemonic power within the European security system. However, recent geopolitical shifts and increasing uncertainty about long-term US commitment make such alignment more contingent and more difficult for European states to sustain. Drawing on historical insights from the informal group of member states acting in coordination with the US within the Quint for the Western Balkans, the article highlights continuities with the ‘coalition of the willing’ formed in response to the war in Ukraine. It demonstrates that informal coalitions complement rather than replace formal institutions, preserving their relevance and resilience in times of geopolitical uncertainty, while simultaneously exposing their dependence on increasingly volatile transatlantic dynamics. In doing so, it reframes informality in EU foreign policy as a mechanism for adaptive governance in the international system and transatlantic coordination against the backdrop of uncertain US commitments.