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The Case for an Ambitious UK/EU Security Cooperation Pact


It is time for the UK to propose a new framework for cooperation on security with our EU neighbours, covering a wide range of shared security and defence challenges. We should be ambitious – unconstrained by the terms or timelines of the Trade and Cooperation Agreement. Some elements might not be easy to agree, but would be in everyone’s interests.


The Context

We should recognise that there is a chequered history of UK engagement on European defence and security.

  • The UK supported the first collective European framework for defence cooperation, the Western European Union, formed after France vetoed a proposed European Defence Community in the 1950s. But the hard defence focus was, and has remained, on NATO.
  • Fast forward, and various attempts to reinforce European defence and security cooperation in the 1990s led to John Major proposing, unsuccessfully, the WEU as the defence pillar of the EU.
  • Tony Blair signed up to closer defence cooperation with France at St Malo, and sought to leverage engagement on security and defence to reinforce the UK’s role in the EU, until Iraq put an end to that.
  • As differences on the economy and migration increased between the UK and our EU partners during David Cameron’s premiership, Theresa May, as Home Secretary, continued to develop police and judicial security cooperation.
  • After the Brexit vote, many argued for continuing foreign policy and security cooperation. Some on the EU side, rightly or wrongly, felt the UK was trying to trade off security for economic advantages.

As PM, May set out an ambitious agenda for shared security cooperation at the Munich Security Conference in 2018. But it got lost in the difficult discussions around the terms of the UK’s departure (the EU’s decision to exclude the UK from the Galileo satellite system didn’t help). Some on the EU side, notably Michel Barnier, did propose a framework for foreign policy cooperation in the Political Declaration. But Boris Johnson’s arrival as PM scuppered that. The Trade and Cooperation Agreement (TCA) includes some arrangements for police and judicial cooperation, but however effective these may be they are pared down. The TCA is silent on foreign policy, wider security and defence.

Is this really good enough? Much has changed in seven plus years since the Brexit vote. Tempers have cooled. There is greater pragmatism in the relationship.

Crucially, too, the world has changed around us. It is both more complicated and more dangerous, not just with the immediate challenges of Ukraine and the Middle East, but wider instability across sub Saharan Africa, developments in US/China relations and the emergence of a range of ‘middle powers’ looking to carve out greater influence. Russia’s invasion of Ukraine has refocused attention on hard, collective defence. At the same time, the urgent need to reduce dependence on Russian oil and gas has reignited wider debates on the importance of reinforcing economic and societal resilience.

Geopolitical uncertainty will continue through 2024, this year of elections, with all eyes on what happens in the US. There is a renewed focus on the challenges from a range of state, and non-state, actors; on the need to build economic and energy security; and the need to counter multiple other threats, whether of terrorism, cyber attack, or disinformation. Such challenges, both of hard defence and wider security, affect both the UK and its European neighbours. We have a shared interest in tackling them and the response would be improved by closer cooperation.

The UK and the EU have separately taken a number of initiatives to reinforce their security and defence relationships with key allies and partners. Notably:

  • The UK has invested in AUKUS, and is developing its defence ties with partners like Japan.
  • The EU has reinforced its cooperation with the US, in particular on economic security, through new arrangements like the Trade and Technology Council. It is also reaching out to new partners across Asia, Africa and South America with initiatives like the Global Gateway, both to reinforce supply chains – around critical minerals for example – and to counter Chinese influence.

The UK should continue to reinforce bilateral security and defence relations with European allies like France and the Nordics, but also with the EU (it is not a question of either/or). There are some encouraging signs that this is happening. The UK Government has worked closely with the EU on particular challenges like reinforcing sanctions on Russia, and it appears ready to consider further cooperation – a Conservative Defence Minister recently welcomed the possibility of further cooperation in support of Ukraine. But the heritage of Brexit and the ongoing debate around divergence still constrain the appetite for more structured cooperation. The Labour Party has argued for some time that Johnson’s rejection of structured foreign policy cooperation was a mistake. It supports closer UK/EU foreign policy and security cooperation, including regular summit meetings.


A new security pact?

Resuscitating the Political Declaration dialogue arrangements would be a good first step, but would not take full account of recent shifts in geopolitics, and associated risks. What is needed is a new framework in the mutual interest that recognises the new realities.

EU members, increasingly, tackle their security challenges collectively. The UK is not in the EU and has no role in defining the EU’s ambitions. Indeed, neither side should be seeking to bind the other into particular undertakings if the other side has reservations. But the UK and the EU face, independently, similar security and defence challenges. In a number of areas they would benefit significantly from closer cooperation.

A new framework for cooperation should be enabling, not restrictive, driven by its own logic. It should allow for joint discussion of each particular challenge and provide a process to coordinate EU and UK responses – including, with common agreement, organising a joint response.

* * *

A comprehensive security and defence partnership should cover broadly the following ground. I do not pretend that all these proposals are necessarily right, or could easily be agreed, but they indicate the range and scope of the issues that should be considered (and why leaving this discussion to the TCA review wouldn’t do it justice).



It was during the last UK Presidency of the EU that the number of EU military and civilian/military missions leapt from 4 to 14. While Ukraine has underlined the crucial importance of territorial defence and deterrence delivered through NATO, there will be a continuing perhaps increasing need for EU missions too. The UK should be ready to participate where there is a clear shared objective: in Bosnia (Operation Althea) for example, and against the Houthi threat to international shipping (supporting greater cooperation between Operations Prosperity Guardian and Atlanta). That doesn’t mean signing up to the whole EU common foreign and security policy. The EU is open to the participation of ‘partners’. Issues around funding, organisation, and how missions are badged have been resolved in the past. There is no reason to think that they can’t be again. There is a particular subset of training missions, notably in support of Ukraine, where greater coordination between the parallel UK and EU efforts would surely benefit both.


Capability development

There is a pressing need to boost capability development, and make better use of the capabilities and expertise that exist. For a range of military capabilities the UK should be ready to participate in EU development programmes where there is a clear shared benefit. The Government has already said it wants to join the programme to develop military mobility across Europe for example (as the US has). This is held up politically at the moment on the EU side, which needs to shift. Both sides stand to gain from this kind of cooperation.

It gets more complicated when it comes to longer term defence industry development and procurement. But, again, the need is clear. The EU promised last spring to deliver 1 million rounds of ammunition to Ukraine. So far they have only managed one third of that. Despite efforts, production and procurement are falling short. There is a strong case here for greater coordination and cooperation between allies and partners, including the UK and the EU.

The wider European defence industry development and planning processes are difficult: they involve collective funding; they often favour EU partners; there are strict constraints around any resulting defence intellectual property (as there are for joint projects with the US too); and there are questions about overlap with NATO defence planning. Some of these issues are hard. But that shouldn’t deter the UK from actively exploring the options. Some of the political blocks to boosting European cooperation, including through EU projects and programmes, can be exaggerated. EU/NATO cooperation, including on these issues, is arguably better than ever. Norway has successfully negotiated participation in EU defence projects. The US has an arrangement with the European Defence Agency (EDA), giving it visibility and access. The UK should negotiate an agreement with the EDA at least as good as the US has.

Signing up to collective EU defence funding is a big ask. But there should be scope to look at flexibility, enabling the UK to contribute to the costs of projects in which it is participating and where there is a clear shared benefit. Of course both sides would need to agree that there was a mutual interest, and then to agree the terms. It is noteworthy that funding for military support to Ukraine has been organised ‘off budget’, financing collective support without getting tied up in EU budget contributions.

Planned defence expenditure across Europe has gone up some €200 billion since Russia’s invasion of Ukraine. There are huge opportunities for collaboration. The focus is too often on top end, complex projects like the rival next generation fighter plane programmes (and there is indeed a strong argument for combining these). But there is a lot to do at the less glamorous, more basic level too, in ammunition production for example. Poland is having to procure ammunition from Korea because they cannot source what they need closer to home.

To be clear, none of this should detract from NATO’s role in planning and organising collective defence. European allies are, more than ever, conscious of NATO’s crucial role. But NATO itself has underlined the importance of non-EU allies’ involvement in EU defence efforts as essential for collective security and prosperity.

The US Presidential election is focusing minds. A second Biden administration would support the kind of measures set out here. Were Trump to be re-elected, they would be needed even more. If, at some point in the future, the US chooses to do less in Europe, other allies will need to do more (indeed, there is a strong case for that in any event). Done right, closer cooperation between EU allies and the UK could help to underpin those efforts.



There are a range of EU security and law enforcement agencies that are tackling key shared security challenges, and with which the UK should look to deepen its engagement. The UK proposed this in 2018, but the initiative got lost in the heat of Brexit. It is time to look again, in the mutual interest.

The UK has maintained, or started to rebuild, relations with the agencies that promote cooperation between European police and law enforcement (EUROPOL), prosecutors (Eurojust), and border forces (Frontex), but in each case with limitations which it would be worth looking at again. The UK played a key role in developing these agencies, which exist to combat cross-border security threats like serious and organised crime, terrorism, trafficking, smuggling – and crucially the fight against international gangs involved in people smuggling and ‘small boats’. Fully re-engaging with the EU agencies would involve taking on new commitments, respecting mutual engagements, and some collective funding, which is a tall order. But the shared, benefits are potentially significant:

  • Fully sharing the data these agencies hold;
  • Helping set the policy priorities for future cooperation;
  • Potentially leading operations targeting the gangs and individuals involved.

The costs would be limited, and most practitioners consider that they would represent a sound investment. This is not about undoing Brexit: the European Court of Justice is only involved in specific aspects of the agency’s activities. But the threats are real, and growing. Frontex is on the front line of our collective fight to counter the people-smuggling gangs – indeed the UK should consider offering resources to help in the Mediterranean. This is the kind of commitment to tackling a shared problem that will be required if we are to make progress on renegotiating return agreements or other cooperation on illegal migration with our neighbours.


Law enforcement and judicial cooperation

There are important provisions in the TCA for cooperation, in particular sharing data to tackle criminality (crime scene data, fingerprints, DNA, vehicle registrations), to follow cross-border movements (air passenger data), and to extradite criminals across Europe. But these need to be kept up to date. This is an area where maintaining alignment works for everyone. For example, the UK should be able to opt in to updated sharing of biometric crime scene data (and be able to continue existing data sharing), without this being contingent on a formal renegotiation of the TCA. More generally, as law enforcement data sharing continues to evolve, the UK should stay closely involved, including sharing expertise with the EU where helpful. The UK’s experience with access to cross-border electronic evidence, for example, could be helpful. It is an area in which the EU is also seeking an agreement with the US.



A subset of this kind of cooperation is tackling cyber and hybrid threats and countering mis- and disinformation. The EU has made important progress on this; it has reinforced its cyber agency (ENISA) and enacted important legislation against online crime and abuse. The UK has much to offer, and made a significant contribution to EU thinking when it was a member – for example around improving cyber security around elections. The Government has recently launched a dialogue with the EU, but there is scope to go further, and real mutual benefit in strengthening cooperation on these challenges.


Crisis management and emergency disaster response

Unfortunately, these are areas of growing importance, not least given the frequency of climate-related emergencies. The UK and the EU have well developed civil protection mechanisms, bringing together military, other state and voluntary sector resources. Again, there is obvious potential mutual benefit in strengthening cooperation.



The EU, including the UK when it was a member, has invested heavily in satellite technology and infrastructure. The UK and EU have agreed to restart cooperation on environment and climate change earth observation through the Copernicus satellite system. But not, yet, on security. The UK was excluded from the restricted part of the EU’s satellite navigation system Galileo during the Brexit process because it wasn’t deemed a trusted partner. Again, the world has moved on. The EU should be encouraged to review this decision, and the UK to explore the full range of options for non-EU members’ involvement with Galileo.



European countries’ intelligence agencies work together, to tackle terrorism for example, and this happens outside the EU structures. The UK remains fully involved in this work. EU countries also pool intelligence for other purposes, to support EU military and civilian/military missions or to develop a better understanding of events or developments directly impacting European interests. The UK’s capabilities in this area are, rightly, highly regarded, and we should look again at how they might be put to the service of EU partner agencies and EU institutions, where there is a clear shared interest.


Economic security/sanctions

The UK and the EU have established close cooperation on sanctions policy and implementation against Russia following the invasion of Ukraine. This has been an important part, working very closely with the US, of implementing G7 and international sanctions (and now tackling circumvention). Building on this positive experience, the UK should explore expanding this cooperation with the EU to wider sanctions policy and implementation in other cases. As sanctions play an ever bigger role in crisis management and security policy this will be important in its own right and as a basis for wider security cooperation.

Indeed, economic security, building resilience – physical, infrastructure and societal – and reducing dependencies is increasingly key to security policy. The EU, playing to its strengths, has been active: coordinating Europe’s radical reduction in dependency on Russian oil and gas, exploring alternative energy sources, tackling emerging dependencies from Chinese telecoms, tech and chips to critical minerals, and building or reinforcing links with like-minded countries from the US, through the Trade and Technology Council, to Asia, Africa and South America through the Global Gateway initiatives. The UK has pursued a number of initiatives in parallel. All would benefit from closer cooperation on this range of issues. To take one example, as the US works to define its technology relationship with China, including through a series of restrictions on trade and investment, the UK and EU could benefit enormously from closer coordination of their responses to the fallout from the push to ‘de-risk’ relations.


Energy security

One specific aspect of economic security where the UK and the EU have an obvious shared interest is energy security. The UK has re-engaged with the framework for energy cooperation in the North Sea, with neighbouring countries and with the EU. This is a good basis for cooperation on offshore wind and electricity interconnection. But given the increasing importance of energy security policy across Europe and internationally, and the interlinkages with green economic and climate policy, the UK should seek a wider dialogue with the EU on these issues, including on the coordination of our emissions trading systems and the implementation of the EU’s and UK’s respective carbon border adjustment mechanisms.



I realise this covers a lot of different aspects of security, raising different opportunities and issues. But the world has changed. Defence and security challenges are more urgent and more diverse. The UK and the EU face essentially the same challenges, and could face them with more confidence if they worked more closely together. Brexit is behind us. The UK needs a different lens through which to frame its relationship with its neighbourhood; one rooted in and justified by today’s challenges. It is time to develop a new security pact.


Sir Julian King is a member of the European & International Analysts Group and was EU Commissioner for the Security Union, 2016–2019, having previously served as Chef de Cabinet to Baroness Ashton of Upholland, European Commission; Director General Economic & Consular, Foreign & Commonwealth Office; and British Ambassador to Ireland and France