Working paper

The European Union and the war in Ukraine: more money, but not more Europe

This Working Paper analyses the drivers of rearmament and especially military aid to Ukraine

Publishing date
11 December 2025
WP 31

Since Russia’s invasion of Ukraine in February 2022, the European Union has rallied to Kyiv’s support, mobilising large sums to enable Kyiv to fight back. However, unlike previous crisis situations, when new powers were transferred to the EU level and the outcome was institutional deepening, the EU has since early 2022 not overcome collective-action problems associated with pooling military responsibilities and financing common defence. Instead, a subgroup of EU members geographically close to Russia, and with available fiscal space in 2022, has accounted for most military aid to Ukraine and most spending on Europe’s broader rearmament. 

With geography immutable and fiscal positions only alterable very gradually, these ‘coalitions of the willing’ are likely to remain responsible for most of Europe’s direct military response to Russian aggression. Meanwhile, the EU as a whole will continue to fulfil the leading financial provision role for Ukraine’s defence and, through Kyiv, the emerging creation of a credible independent European military deterrent against Russia. Given the uniquely serious effects of armed aggression, the failure of the EU to agree more political and institutional integration since early 2022 makes future EU crisis-driven integration less likely. 

I am indebted to my Bruegel and PIIE colleagues Adam Posen, Nicolas Véron, Angel Ubide, Olivier Blanchard, Cullen Hendrix, Maury Obstfeld, Patrick Honahan, Alan Wolff, Guntram Wolff, Jeromin Zettelmeyer, Zsolt Darvas, Lucio Pench, André Sapir and Stephen Gardner for constructive comments on an earlier version of this manuscript. All remaining errors and possible absurdities remain the sole responsibility of the author.

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