What Can the New Government’s Proposed UK–EU Security Pact Achieve?

Fresh priorities: Defence Secretary John Healey leaves 10 Downing Street after taking part in the new government's first Cabinet meeting on 6 July. Image: PA Images / Alamy

Post-Brexit UK–EU security cooperation has grown since Russia’s 2022 invasion of Ukraine. Practical cooperation on sanctions and support for Ukraine has opened other possible avenues for collaboration. The new Labour government wants an ambitious structural alignment with the EU, but it is uncertain exactly what it could achieve.

Russia’s war on Ukraine has driven a better UK–EU working relationship, especially on Russian sanctions, diplomatic support for Ukraine, and coordinating military training programmes for Ukrainian recruits. This improvement is best illustrated by the resolution of the dispute over the Northern Ireland Protocol through the Windsor Framework. This has happened without any formal agreement on foreign, security and defence policy cooperation, which was omitted from the 2020 Trade and Cooperation Agreement (TCA) that governs the post-Brexit UK–EU relationship. Indeed, the previous government was concerned over the potential ‘overstructuralisation’ of cooperation with the EU on international affairs.

In contrast, the new government has been vocal about a new UK–EU relationship and ‘reconnecting’ with the continent after Brexit. Foreign Secretary David Lammy has designated the EU as his number one foreign policy priority, including structured foreign policy dialogues, which could lead to an ambitious ‘UK–EU security pact’. This reconnection has started immediately with the foreign secretary travelling to Berlin – key to unlocking better UK-EU relations and the target for a new bilateral defence and security treaty – within the first 24 hours.

Meanwhile, Defence Secretary John Healey wants a ‘UK–EU defence pact’ as a ‘bespoke relationship’ that could include UK third-party participation in EU military and civilian Common Security and Defence Policy (CSDP) missions and enhanced cooperation on ‘internal’ security issues such as illegal migration, border control and terrorism.

What Might the EU Think?

These collective propositions, alongside Labour’s UK–EU trade ambitions, bear some resemblance to Theresa May’s ‘dual pillar’ proposals during Brexit negotiations. At the time, the EU did not enthusiastically respond, nor did it offer detailed counterproposals that would have superseded extant third-country arrangements.

EU leaders and officials have been both welcoming and non-committal on closer UK–EU cooperation. The EU has a range of existing formal agreements with third countries, and the UK is unique in not having such a relationship. They conform to similar templates, and none are bespoke (excepting the US) along the lines that the Labour Party wants. The UK’s capabilities and prominent role in European security should give weight to a distinct relationship. However, beyond rhetoric from the EU’s leadership, there appears to be a lack of imagination and an absence of political will to conceive of a future relationship that would deliver maximum value and mutual benefit.

The Politics are Getting More Challenging

In the context of UK–EU relations, political conditions in London have stabilised at the exact same time as they have become more complicated in Brussels. As last month’s EU Parliamentary (EP) elections demonstrated, the politics of the EU looks to be moving to the right as the UK gets its first left-of-centre government in 14 years. The impact of the EP results is already being felt. French President Emmanuel Macron immediately called for a national parliamentary election as the far-right National Rally defeated his Renaissance Party 32% to 15%. While the National Rally fell short of its own expectations in the subsequent election, Marcon’s authority is still weakened and it will be challenging keeping his new centre-left coalition together. The EP result for the opposition Christian Democratic Union and the far-right Alternative for Germany also reinforced the sense that German Chancellor Olaf Scholz’s coalition government is a lame duck, with over 14 months to limp on. Elsewhere, existing authoritarian inclinations in Hungary are complemented by right-leaning leaderships in Slovakia and the Netherlands. Others might follow.

The purpose of any UK–EU cooperation should first and foremost be to deliver additional value for European security as it faces its biggest crisis since the Second World War

However, there are opportunities for the UK to use its considerable political influence with EU member states, especially in defence and security policy, which has grown since the 2022 invasion. As an example, in Estonian Prime Minister Kaja Kallas, the newly nominated High Representative of the Union for Foreign Affairs and Security Policy, the UK has a powerful advocate for stronger UK engagement at the heart of the EU’s institutions. However, the emerging EU political landscape will require careful management by the new government. In some instances, such as the special relationship that had developed between former Prime Minister Sunak and Italian Prime Minister Giorgia Meloni and her political ascendency in the EU, relationships may prove to be more rather than less complicated with the change of government in the UK.

What is the Objective?

The primary driver for Labour’s UK–EU pact seems political – drawing a clean break with the previous Conservative approach. However, this focus confuses means and ends. The purpose of any UK–EU cooperation should first and foremost be to deliver additional value for European security as it faces its biggest crisis since the Second World War. Sunak’s government has already done some of the work by jettisoning some of the Brexit divisiveness and rhetoric such as ‘Global Britain’. This must be furthered to capitalise on the unity that support for Ukraine has fostered and to stress that the UK and EU are allied in a shared common purpose to strengthen European security.

London should therefore be less obsessed with potential structures and getting a formal agreement over the line, and more driven on those areas where stronger UK–EU cooperation adds real value and cohesiveness to European allies and partners as they continue to respond to Vladimir Putin’s destabilisation of European security. Labour’s use of the language of a ‘security pact’ with the EU is eye-catching, but of greater value are the substantive issues rather than the packaging.

There is also a cost to an agreement that is intended to encapsulate and facilitate a wide range of areas of cooperation. For the EU, the more ambitious the agreement, the more policy areas governed by different EU legal and decision-making arrangements it will have, making it longer and more complicated to negotiate and ratify.

London should also be prepared for a heavy dose of realism as to what a pact might deliver, regardless of its ambition, as value for both sides is not a given. Indeed, even when the Labour government under Tony Blair set up the European Security and Defence Policy – the precursor to CSDP – in 1998, alongside France and against advice from his own diplomatic and military establishment, it was not a priority for the UK. It failed on its central ‘Helsinki Headline goal’, and the UK continued to align most closely with the US and NATO in the major conflicts that followed in Iraq, Afghanistan and Libya.

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The UK will inevitably experience frustrations as a partner of the EU, with different tempos in their respective policymaking machinery. As recent examples, the UK and EU have both embarked on counter-Houthi naval operations in the Red Sea and training for Ukrainian soldiers, but it took the EU a considerable time to agree on the structure for its own missions. In the interim, the UK made other arrangements – supporting the US in the former and choosing to establish its own Ukraine training mission, where the speed of implementation attracted the participation of Finland and Sweden – then EU but not NATO members – in advance of the establishment of the EU Training Mission. An agility disparity would likely persist even if a formal UK–EU agreement is reached.


The new UK government should focus on agreeing a ‘UK–EU Joint Declaration on defence and security’ as soon as practically possible to set a strong direction of travel. This would affirm the designation of each party as key allies who should engage in foreign, security and defence cooperation of a scale and scope that reflects their status. The Declaration would also set out a roadmap for substantive areas of cooperation to form building blocks for a modernised relationship. If this could be agreed in the remainder of this year, the UK could then use its strong relationship with Poland - as it takes over the rotating EU Council Presidency from 1 January 2024 – to undertake the substantive negotiations, also knowing the outcome of the US presidential election.

Such a Declaration would not conflict with the existing TCA, nor require its revision. However, the periodic review of the TCA, first set for 2026, might be used to reconsider whether the limited provisions that it contains on UK–EU cooperation on international issues might be adjusted to be more expansive. The TCA review timetable would also align with the announced timeline for the Strategic Defence Review that Labour has pledged for its first year in office. This would allow for clarity from a new UK government as to the ideal form and function of cooperation with the EU on defence and security. Moreover, it would be wise to keep defence and security policy as a separate mechanism from the TCA in order to increase flexibility in a fast-changing European security environment.

What Substantive Areas Should It Cover?

A UK–EU Declaration should prioritise substantive areas for cooperation, rather than institutional landmarks, as the key to a close relationship.

First, there needs to be a full alignment of Ukraine and Russia strategies for the long term. Supporting Ukraine to liberate its territory and denying Russia any strategic benefit from its invasion is a shared priority. While the current political strategy is set in NATO and the G7/Quad, as Ukraine moves down the road towards EU and NATO membership, there will be a need for better UK–EU coordination. The UK no longer has a say in EU enlargement, but it does have a significant stake in its successful conclusion – and, unlike the EU, the UK has a direct say in NATO’s enlargement. Both the EU and the UK will have a shared interest in Ukraine’s dual membership tracks proceeding in a synchronised manner.

Second, there is China and the Indo-Pacific. The UK and the EU both have Indo-Pacific strategies, alongside five other individual European countries. As such, the broad European approach to China is disconnected and very piecemeal in some areas. At a minimum, the EU and UK need closer coordination (notably on the Indo-Pacific), especially as the UK is making long-term defence commitments through AUKUS and the Global Combat Air Programme that will be more effective if better coordinated. Moreover, for both the UK and the EU, greater European coordination may be necessary to manage any deconfliction with the US in its intent and interests in the Indo-Pacific.

The Labour Party has acknowledged that a more coherent UK–EU relationship on foreign, security and defence policy would be beneficial, but it needs to make its ambitions more concrete

Third, the idea of an EU Defence Union now has a strong grip inside Brussels and some national capitals. The UK interest is in an ‘open’ form of strategic autonomy and to embrace the EU as a vehicle for enhancing member state defence capabilities through encouraging greater economies of scale in defence procurement and driving down inefficiencies and duplications. A UK recognition that the EU is now an actor in European defence could be translated into greater advocacy for EU–NATO cooperation, rather than the current ambivalent position. The UK’s expectation might then be that the EU is more accommodating of the UK within its current defence industrial policy ambitions.

Fourth, the emerging EU defence industrial policy ecosystem is largely closed to third countries (excepting EEA states). The direction of EU policy is of significant interest to the UK as a large defence industrial player and – just as importantly – if EU policy succeeds, European defence capabilities development will have a positive impact on what the 23 joint EU–NATO members contribute to assets available to the Alliance. The UK’s defence industrial footprint and its collaborative programmes with European states are an asset of benefit in any plan to rebalance the European and US contributions to European security.

Fifth, third-party participation of the UK in CSDP missions would be of greatest benefit to the EU, with its Strategic Compass focus on Crisis Management. The former has an expeditionary mindset and capabilities to back this up. The UK-led Joint Expeditionary Force is a practical example of the benefits of setting significant ambitions for European states to operate collectively for pronounced effect.

Sixth, intelligence. There is a significant disparity between UK and EU intelligence capabilities. The EU would benefit greatly from UK intelligence in all domains. The UK would also be able to actively contribute to the development of a European intelligence capability that addresses shared collective challenges more effectively.

Getting It Over the Line

While Russia’s war on Ukraine has demonstrated that shared interests can drive the UK and the EU to work closely together, there is a need for both sides to think long-term for the benefit of Europe. The Labour Party has acknowledged that a more coherent UK–EU relationship on foreign, security and defence policy would be beneficial, but it needs to make its ambitions more concrete. Thus far, the EU has not felt compelled to set out its own agenda for future security cooperation with the UK. Leadership changes in Brussels and London will allow for a stock-take of where cooperation might be enhanced. Moving quickly – especially in a climate in which US leadership may be in a state of flux – will be important, but ambitions for an enhanced relationship should privilege policy substance over a push for expansive formal agreements.

The views expressed in this Commentary are the authors’, and do not represent those of RUSI or any other institution.

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Ed Arnold

Senior Research Fellow, European Security

International Security

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Professor Richard G Whitman

Senior Associate Fellow

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