Five years after the United Kingdom's withdrawal from the European Union, the geopolitical situation has changed dramatically. Russia's full-scale invasion of Ukraine has brought war back to European soil, and Donald Trump's return to the Oval Office is challenging the transatlantic partnership.
In this tense situation, relations between the EU and the UK have gained new momentum, particularly through the Security and Defence Agreement signed in May 2025. In addition, the government of British Prime Minister Keir Starmer is increasingly seeking bilateral agreements, such as the Trinity House Agreement with Germany. At the same time, smaller cooperation formats such as Weimar+ or the Joint Expeditionary Force are gaining importance.
Nevertheless, in a recently published defence strategy review, the UK emphasises a ‘NATO first’ approach. However, co-operation at lower levels can help to speed up processes and decisions and strengthen NATO's global position. This includes bilateral and multilateral arrangements within international party structures. Consequently, the approach is not ‘NATO only’.
As the United States is expected to strengthen its foreign policy orientation towards Asia regardless of the Trump administration, the United Kingdom emphasises the importance of European cooperation. The challenges of translating political will into industrial reality can be seen, for example, in competing projects to develop a next-generation fighter aircraft, where the UK, Italy and Japan on the one hand and Germany, France and Spain on the other are developing models independently of each other. What are the prospects for the UK to become a more integral player in European security? Can the UK build on its bilateral and minilateral relationships to make Europe resilient in the face of growing global and regional challenges?
These and other questions were discussed by participants at a confidential breakfast debate at IEP with Julie Smith, Professor of European Politics at the University of Cambridge, defence spokesperson for the Liberal Democrats in the British House of Lords as Baroness Smith of Newnham and member of the Academic Advisory Board of IEP. The event was moderated by Prof. Dr Funda Tekin, Director of IEP.
The event was organised with the kind support of the European Commission and the German Federal Foreign Office.
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