Cautious Cooperation: The Limits of the New UK-EU Defence Partnership
By Sam Paquette
On May 19th, 2025, EU and UK leaders met in London to recalibrate relations for the first time since the UK left the EU in 2020. One of the summit’s main outcomes was Prime Minister Keir Starmer and European Commission President Ursula von der Leyen establishing a new UK-EU Security and Defence Partnership, creating a political framework to maintain regular dialogue on defence issues between UK and EU officials. This initiative marks a new phase of cautious UK-EU defence cooperation, as both sides are driven closer by Russia’s full-scale invasion of Ukraine and uncertainty about the US’s long-term security commitments for European defence.
The new agreement focuses on areas of shared concern, including space security, disruptive technologies, maritime security, hybrid threats, counterterrorism, climate-security nexus and global health. The agreement also encourages the UK to participate in EU defence initiatives, such as the EU’s Common Security and Defence Policy and to boost the UK’s participation in the EU member states’ PESCO projects aimed at enhancing their defence capabilities. Despite these new collaborations, some analysts contend that the partnership fails to address critical challenges facing European defence, such as the US withdrawal of its security commitments, and does not establish the necessary institutional mechanisms to mend these challenges.
A problem that exemplifies this insufficient collaboration is the fact that defence industry integration, an issue crucial to the national security interests of both sides, is not included as a central objective in the agreement. The UK has a substantial defence industry and is essential for strengthening Europe’s defence posture, meaning defence industry integration should be included as a central objective. Even the EU’s other defence agreements with non-EU members, such as with Norway and Ukraine, have defence industry cooperation as a core goal. A separate statement was released describing that the UK can access the EU’s €150 billion SAFE program to plug gaps in EU defence capabilities and support the development of Europe’s defence industry. This statement sets the groundwork for defence industry collaboration, but it still falls short. The new UK-EU partnership demonstrates that both parties are forming issue-based coalitions while avoiding rigid commitments related to their national interests, through modest steps towards rapprochement.
Since Brexit, the EU and the UK have developed distinct political trajectories and challenges in their defence sectors. The UK frames itself as a global actor emphasizing its strategic role in NATO and its bilateral defence agreements with non-EU states, while the EU has a renewed focus on achieving strategic autonomy. These differences are captured in a policy paper released at the summit. For their respective defence industries, the UK is constrained by industrial decline and underfunding, while EU member states face capability gaps and have differing threat perceptions. Ultimately, the new security partnership functions as a pragmatic mechanism to address these constraints but does not establish sufficient institutional linkages to create the foundations for a robust European security architecture.
In conclusion, the recalibration of EU-UK relations in defence and security represents a modest shift in strategic relations in the post-Brexit period. While the EU-UK defence partnership establishes a dialogue of shared mutual interest, it avoids making deeper institutional commitments and omits key issues like defence industrial cooperation and strategic autonomy. The partnership underscores cooperation driven by short-term alignment and interests rather than a shared strategic vision to enhance European defence. For now, this agreement serves as a symbol of cautious rapprochement between the two sides.