Understanding Coalitions of the Willing

Few terms have travelled as fast in European security debates as the "coalition of the willing." Coined during the Iraq war in 2003 and long tainted by that association, the concept has been revived by Russia's war against Ukraine and turned into one of the driving formats for structuring European support for Kyiv. Yet the phenomenon reaches further: coalitions of the willing are increasingly prominent in European governance in general, and in security and defence in particular. Flexible, ad hoc groupings of states cooperating outside or alongside formal EU frameworks, they are characterised by informality, speed and purpose-orientation. The implicit promise is twofold: that they will contribute positively to European security, and that they will strengthen Europe's capacity to act. A new paper by Christos Katsioulis (Friedrich-Ebert-Stiftung), Funda Tekin (Institut für Europäische Politik) and Ilke Toygür (IE University) puts that promise to the test, asking whether coalitions of the willing are an effective instrument of governance for European security and defence, and whether they increase the EU's capacity to act.

The findings show how the format delivers, and where it falls short:

Informality cuts both ways. Coalitions of the willing let states circumvent procedural constraints and coordinate rapidly in a crisis, but at the cost of legal certainty, procedural clarity and enforceability: coalitions typically lack binding commitments, clearly defined decision-making rules and robust monitoring mechanisms.

Output legitimacy comes at the expense of input legitimacy. Justified by their capacity to produce timely results, coalitions rest on selective participation and are not subject to the procedural safeguards of formal EU decision-making, thereby risking the exclusion of certain member states.

Capabilities and political will diverge sharply. Within the Coalition of the Willing for Ukraine, observers distinguish the "willing and able" (France and the UK), the "willing but constrained" (Canada and Sweden) and the "hesitant and doubtful" (Germany, Poland, and Italy).

Decision-making drifts away from EU institutions. As policymaking shifts from formal EU formats, where the European Parliament, Commission and Court of Justice play their Treaty-defined roles, to informal and selective settings, citizens may find it harder to identify who is responsible, weakening democratic accountability.

These dynamics point to a structural tension at the heart of European integration: reconciling decision-making efficiency with democratic legitimacy and institutional coherence. Left unanchored, the authors warn, coalitions risk a self-reinforcing cycle in which bypassing common institutions becomes politically cheaper, entrenching fragmentation and weakening institutional cohesion.

Yet the format has proved its worth. Convened in London in March 2025 under French and British leadership, the Coalition of the Willing for Ukraine filled the leadership vacuum left in the Ukraine support coalition by the US administration, strengthened Ukraine's position in the Russian-American negotiations, and made it difficult for Washington and Moscow to continue overlooking European positions. Its informal character allowed participating states to sidestep less like-minded partners while alleviating others' fears of exclusion or fragmentation.

The paper concludes with a clear list of dos and don'ts: coalitions of the willing are a good instrument for political signalling, rapid reactions to urgent needs, narrowly defined military operations, and actions funded by participating states. They become the wrong option when democratic legitimacy is needed at the supranational level, when long-term financial decisions require stable legal grounds, or when they rely on institutional frameworks without a clearly defined interface with the EU.