On March 16, 2021, the UK government published its Integrated Review of Security, Defense, Development, and Foreign Policy, the most comprehensive presentation on British external policy in several decades. The document sets out an optimistic vision of a “Global Britain,” which, thanks to its great resources and strong networks of friends, will successfully navigate an increasingly complex and contested world. Most of the early debate since the document was published has focused on the question of whether the UK’s envisaged tilt toward the Indo-Pacific is in line with the country’s capacities and interests, the planned nuclear rearmament, and the temporary reduction of development assistance.

Although Brexit was an important motivation for the policy review, the paper deals with the UK’s future relationship with the EU in a perfunctory way. In the few sentences devoted to this subject, the government mostly celebrates the UK’s new freedom to “pursue different economic and political approaches . . . where this suits our interests.” The document does, however, recognize “the important role played by the EU in the peace and prosperity of Europe” and, intriguingly, envisages finding “new ways of working with [the EU] on shared challenges.” What these new ways might be is left unsaid, while several pages are devoted to various aspects of the UK’s future engagement in the Indo-Pacific.

Stefan Lehne
Lehne is a senior fellow at Carnegie Europe in Brussels, where his research focuses on the post–Lisbon Treaty development of the European Union’s foreign policy, with a specific focus on relations between the EU and member states.
More >

Even though the UK’s review document therefore mostly avoids the subject, it is still a good occasion for a reality check on the consequences of Brexit on EU foreign policy. How has the UK’s departure affected the EU’s capacity in this field? How has Brexit changed the political dynamics in the EU and the role of the UK? And what is the potential for cooperation and competition between Brussels and London going forward?

How Big a Loss?

Throughout its time in the EU, the UK stood out among its partners for its wealth of foreign policy resources. Membership in all the key global networks and institutions, a first-rate foreign service, a capable military and intelligence apparatus, London’s status as a major financial center, and world-class universities and media gave the UK international influence that greatly transcended its economic and demographic weight.

The January 2020 departure of one of the EU’s strongest foreign policy actors dealt a massive blow to the union’s prestige and soft power around the world. Particularly during the first months and years after the UK voted in a June 2016 referendum to leave the union, many expected Brexit to mark the beginning of the EU’s terminal decline. However, no other country followed the UK to the exit, and during the difficult years that followed, with former U.S. president Donald Trump in the White House and the coronavirus pandemic, the EU proved more resilient than many had thought.

The EU’s weakness as a diplomatic actor and a manager of international crises is a consequence of dysfunctional decisionmaking structures, the lack of a common strategic culture, and internal divisions. Just as the UK’s participation did not allow the EU to overcome these hurdles, so the UK’s departure did not change the picture greatly for the worse. In multilateral diplomacy, where the EU traditionally plays a more important role, the union continues to have significant clout despite the British exit. With its twenty-seven members and its financial firepower, the EU remains one of the strongest forces in international organizations and multilateral negotiations—at least it will as long as its members manage to agree on common policies.

It is also true that not very much of the UK’s impressive foreign policy potential was deployed in support of EU policies. Whereas Germany always has wanted to take part in a European foreign policy and France insists on leading it, the UK never really identified with the project. Whenever strengthening the EU’s foreign policy tools came up for discussion, the UK consistently emphasized the primacy of national external action. It was at London’s insistence that a declaration was attached to the EU’s 2007 Lisbon Treaty stating that the treaty’s foreign policy provisions “do not affect the responsibilities of the Member States, as they currently exist, for the formulation and conduct of their foreign policy nor of their national representation in third countries and international organisations.”

The UK’s reservations about the objective of a common foreign and security policy were particularly evident in the area of defense, where, thanks to its assets in this field, the UK easily could have played a leading role. Apart from a brief period after the 1998 St. Malo Declaration of then UK prime minister Tony Blair and French president Jacques Chirac, London preferred to hinder the development of EU defense projects, arguing that such steps risked undercutting NATO’s primacy in European security. After Brexit, with the UK’s hand removed from the brake, EU security policy promptly started to make progress; permanent structured cooperation, which allows able and willing member states to work more closely on defense, and the European Defense Fund have been the most important outcomes so far.

Looking at the United States as its principal partner, the UK considered the EU one of several international forums to be used as a force multiplier. When London chose to engage, it was usually highly effective in shaping EU policies. With its practical approach to foreign policy, the UK often helped find an acceptable course of action between the ambitions of France and the inhibitions of Germany. As a strong supporter of EU enlargement, London contributed to the union’s greatest foreign policy success. It often built bridges not only to the Nordic countries but also to Central and Eastern Europe, and the UK’s uniquely extensive network and reach strengthened the EU’s global perspective.

However, over the last decade, with an increasingly Euroskeptic Tory party in charge in London, the UK downscaled its conceptual and operational involvement and focused primarily on particular areas, such as sanctions policy. As for civilian and military operations, with the exception of the Atalanta antipiracy operation, the UK disengaged long before Brexit. For these reasons, too, the UK’s departure left a somewhat smaller hole in EU foreign policy than the country’s formidable capacity would lead one to believe.

How Great a Change?

It is hard to assess the full impact of the UK’s withdrawal because Brexit has come at a time when EU foreign policy is going through an exceptionally difficult period. The priority of tackling the coronavirus pandemic and its economic fallout has resulted in a loss of momentum for any issue not connected to this agenda. Despite the acute crisis, the EU has managed to develop instruments to tackle climate change and has pursued an active trade policy, but little energy has been left for foreign and security policy.

Whether dealing with ongoing antigovernment protests in Belarus, tensions in the Eastern Mediterranean, or the troubled situation in Libya, EU foreign ministers have experienced increasing difficulties in achieving agreement in the EU Council. Meanwhile, the union’s institutional leaders have lacked the support to take initiative, as the much-criticized visit by the EU’s foreign policy chief, Josep Borrell, to Moscow in early February 2021 showed. The ambitious rhetoric about a “geopolitical [European] Commission” and an EU that has to “learn the language of power” that marked the early days of the commission of President Ursula von der Leyen in late 2019 sounds rather hollow at present.

The UK’s break with EU foreign policy was more radical than the remaining twenty-seven member states had anticipated. The political declaration that had been negotiated by former UK prime minister Theresa May and was attached to the October 2019 Brexit withdrawal agreement included provisions about “ambitious, close and lasting cooperation” between the UK and the EU on foreign and security policy, indicating various areas where the two sides could continue to work together.

However, when it came to negotiating an agreement on the future relationship between London and Brussels, the government of Boris Johnson, who succeeded May as UK prime minister in July 2019, showed no interest in this area at all, preferring a full and clean rupture with EU foreign policy. In his speech at the February 2021 Munich Security Conference, Johnson asserted that Brexit had restored the UK’s sovereignty over vital levers of external action—though in reality, there is little evidence that EU membership had ever seriously constrained the country’s foreign policy.

The Brexiteer ideology demanded that the UK should be free to pursue the Global Britain agenda without being held back by cumbersome institutional arrangements with its former partners. The UK government probably also felt that being part of various informal consultative groups—including the European Three (E3) of France, Germany, and the UK and the (European) Quad of the E3 plus the United States—would give it sufficient influence on EU foreign policy. In his speech in Munich, Johnson underlined his high expectations regarding future cooperation within the Quad.

E3 cooperation had its origins in a joint trip of the three countries’ foreign ministers to Tehran in 2003. That visit initiated a diplomatic process that eventually led to the 2014 Joint Comprehensive Plan of Action (JCPOA) on the Iranian nuclear program. As the EU foreign policy chief was later co-opted into the negotiations, the format enjoyed broad acceptance, including from other EU member states. Since the UK’s departure, E3 cooperation no longer takes place within an EU framework, but that has not made the group obsolete. On the contrary, the E3 since has met more frequently than before, including as a first meeting of defense ministers in August 2020, and it has adopted dozens of declarations covering a wide variety of subjects. Most of this output has concerned Iran and various Middle Eastern issues, but some have dealt with matters ranging from the South China Sea to Venezuela.

France and Germany have valued staying close to a significant player like the UK and have appreciated the informality and flexibility of a mechanism that has allowed more rapid responses to developments than heavy EU structures. London, for its part, particularly welcomed working with Paris and Berlin when, during the Trump administration, cooperation with Washington was less productive than at other times. Other EU members and the EU institutions have perceived the intensified E3 cooperation less positively. A statement on an international issue that includes France and Germany prejudges any possible EU position on the matter. In many cases, it is even questionable whether the adoption of an EU position after an E3 statement will add any value. This reduces the ability of other member states to have a say and weakens the relevance of EU foreign policy.

Unlike in other areas of the EU’s work, where Brexit has prompted realignments of member states—such as the Frugal Four of Austria, Denmark, the Netherlands, and Sweden on budgetary questions or the New Hanseatic League of the Netherlands and the Baltic and Nordic states on trade—no such new groupings have yet appeared in the area of foreign policy. However, it appears likely that the prominence of the E3 could accelerate tendencies toward fragmentation. If France, Germany, and the UK do their own thing, other like-minded groups will follow their example. The high-profile roles the Baltic states and Poland played in support of democratic change in Belarus is a case in point. There are already several elements of factionalism, such as the French intervention initiative, in which only some member states participate, or the 17+1 forum, which brings central and southern EU member states together with China. Other discontented member states might simply lose interest in a common EU approach and focus on pursuing their own national foreign policies.

So far, however, E3 cooperation has remained limited to diplomacy, and no operational action has been taken through that framework. When it comes to sanctions, military or civilian missions, trade or other sectoral agreements with third countries, financial assistance, state building, and training programs, the EU’s instruments have lost none of their relevance and value. But these instruments can be deployed effectively only if there is a functioning link between the conception and conduct of diplomacy, on the one hand, and its operational support and implementation, on the other. The former cannot be outsourced to a small group, leaving the rest of the EU to supply the toolbox for the latter.

There are therefore limits to the potential of E3 cooperation. If it alienates other EU member states, it will eventually blunt the instruments on which the big member states also rely. If France and Germany wish to lead EU foreign policy, they will have to do so from the inside, because they need the support of all the other twenty-five members. The idea that London could shape EU foreign policy through its informal cooperation with Berlin and Paris will probably not work out. And this leads to questions of what a productive partnership between the EU and its neighbor across the English Channel would look like and how it could be brought into being.

Partners or Rivals?

Four main factors will determine the character of EU-UK relations in the short and medium term. The first is quite negative: the emotional and political fallout from a difficult divorce. The second is positive: a revived transatlantic relationship that could push the UK to reengage with the EU. The third concerns external challenges, and the fourth relates to the respective internal policy trends in the UK and the EU. Both of the last two could have the effect of pulling the two sides closer together but could also push them further apart.

Divorce Pains

Shortly after leaving the EU, the UK government made clear that it considered the EU ambassador to London a representative of an international organization and would not grant this official the full diplomatic status given to representatives of states. Given that the EU’s 142 other delegates around the world all enjoy this status, Brussels considered this an unfriendly step and responded by limiting the access of UK diplomats to the EU institutions. This minicrisis has few practical implications. But it demonstrates that, at least initially, the UK government felt the need to highlight its rupture with Brussels through undiplomatic behavior.

A much more serious problem is the unfinished business of Brexit. The December 2020 EU-UK Trade and Cooperation Agreement left unresolved many issues that will require further difficult negotiations. The implementation of some elements of that accord and of the Northern Ireland Protocol to the Brexit withdrawal agreement, which has led to the need for  border controls between Great Britain and Northern Ireland, has already proved highly contentious. This tension could turn into a permanent source of friction and even a serious political crisis. If the economic damage from Brexit becomes politically harmful, the Tory government will seek to shift the blame onto intransigent behavior by the EU. Finally, political fights and lengthy legal battles could ensue if the Johnson government chooses to diverge significantly from EU standards, as this would trigger countermeasures under the post-Brexit trade agreement’s rebalancing mechanism.

Transatlantic Rapprochement

As with many other divorces, Brexit has a rich potential for irritations and tensions that could for many years hamper the two sides’ willingness to work together. It is fortunate, therefore, that there is one important countervailing force: the strong interest of the administration of U.S. President Joe Biden in intensive cooperation with the EU. Unlike his predecessor, Biden considers U.S. allies among the country’s key assets in global politics. It became clear from the start of his presidency that he does not reserve this reengagement with Europe to the bigger states. Within the first weeks of his tenure, Biden talked on the phone with von der Leyen and participated by video link in a meeting of the European Council, U.S. Secretary of State Antony Blinken joined a meeting of the EU Foreign Affairs Council, and U.S. climate czar John Kerry visited Brussels. Also, both sides promptly moved to defuse some of the trade disputes that had bedeviled the relationship in the past.

As its integrated review underlines, the UK considers a close partnership with the United States its top foreign policy objective. Renewed U.S. engagement with the EU will therefore most likely take London along for the ride. One pilot project in this regard is the plan to restore the JCPOA with Iran. The United States and the E3 are key players here, but the EU institutions will also have to play an important part. Another high priority will be the preparations for the November 2021 United Nations Climate Change Conference in Glasgow. With the UK as the host and the EU and the United States as strong advocates of effective climate transition policies, these parties all will have to work as one coherent team to make this crucial conference a success.

Developing a common transatlantic approach to dealing with China is another major U.S. concern. On the face of it, the positions of the UK and the EU on this question are strikingly similar. The integrated review describes China not only as “the biggest state-based threat to the UK’s economic security” but also as an essential partner on trade and for tackling global challenges. The EU, for its part, sees China simultaneously as “a cooperation partner, a negotiation partner, an economic competitor and a systemic rival.”

In view of the EU’s much greater collective economic weight (compared to the UK), Washington will be particularly eager to persuade Brussels to align itself with U.S. positions. But this will be difficult because EU member states have divergent economic interests and threat perceptions. In the management of this process, the European Commission will be an indispensable partner for Washington. To the extent that a common agenda does emerge—possibly in the framework of a new Transatlantic Council on Trade and Technology, as proposed by the commission—the UK risks remaining outside the room where decisions with implications for its economic and technological interests are made. It is likely that the United States will be keen to include the UK in some form in a transatlantic dialogue on technology. Whether the EU will agree to that proposal will depend on the state of its overall relationship with London.

Despite the warmth of initial contacts, it is unlikely that the old hegemonic partnership between the United States and Europe will be fully restored. Washington’s preoccupation with its internal agenda and prioritization of the Indo-Pacific will probably lead to a further decline of the United States’ political and security involvement in Europe and its neighborhood. And in Europe, there are many who believe that, after the experience of the Trump years and amid uncertainty about the future political orientation of the United States, the EU needs to pursue “strategic autonomy” and avoid relapsing into its old dependence on Washington. It is likely that discussions of NATO’s future strategic concept and, more generally, of the alliance’s NATO 2030 futureproofing initiative will strain the transatlantic relationship and cause divisions between the UK and other European allies.

If the transatlantic relationship becomes more difficult again, possibly after a new power shift in the 2024 U.S. presidential election, that partnership will remain a key factor for the future of EU-UK relations. Depending on the course set by Washington, the UK might seek to position itself as the United States’ staunchest ally and a bridge builder across the Atlantic or even, in some cases, join the EU camp. However, on some geoeconomic issues, where the EU’s collective weight comes into play, the UK risks being marginalized if it cannot fight its way to the table where the crucial decisions are being made.

Outside Pressure

A comparison between the integrated review’s overall analysis of the security situation in Europe and its neighborhood and that of the 2016 EU Global Strategy shows that the twenty-seven EU member states and the UK have broadly similar views. Renewed pressure from Russia on countries belonging to its former empire and Russian attempts to destabilize Western democracies through disinformation and cyber warfare are likely to drive London and Brussels to pursue a concerted policy. The integrated review considers Russia “the most acute threat” to the UK’s security. When Johnson has welcomed the UK’s regained ability to adopt sanctions on a national basis, he probably meant symbolic measures such as blacklisting individuals. Few governments want to be on their own in adopting tough economic measures, as this means being exposed to countermeasures and losing business to competitors. Major challenges from the East are therefore likely to be met with a joined-up Western response that includes the United States.

When it comes to crises in the Middle East and North Africa, the picture is more complex. On policy toward these regions, the EU suffers from chronic internal divisions, and the UK’s views have often been at odds with those of France and Germany. New challenges from this direction would probably lead to consultations primarily within the E3 or the (European) Quad. If a common approach emerges, the E3 will strive to bring the other EU members on board and employ the union’s instruments to support that approach. If the leading countries fail to agree, real crisis management will once again be left to others, most likely Russia and Turkey.

Active competition between the UK and the EU in Europe’s neighborhood remains unlikely, because the two sides’ fundamental interests are largely aligned. This is different in regions more distant from Europe, where the UK can build on its strong global networks. In its integrated review, the UK claims that by 2030 it will be the “European partner with the broadest and most integrated presence in the Indo-Pacific”—an ambition that has a strong competitive ring to it.

As chair of the Group of Seven (G7) in 2021, Johnson aims at including Australia, India, and South Korea in a new Democracy Ten (D10) grouping. He wants the UK to join the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, a trade agreement among countries bordering the Pacific, and he is reportedly interested in joining the other Asia-oriented Quad of Australia, India, Japan, and the United States, a group so far primarily concerned with containing China’s military rise. The EU, for its part, has strong economic relationships with most Asian powers but has a lot of catching up to do on foreign and security policy.

Internal Developments

The respective internal developments within the UK and the EU are the fourth factor that will determine whether the UK-EU foreign policy relationship will be primarily cooperative or competitive. At this point, it is possible only to identify some trend lines that could be relevant.

On the British side, an obvious trend concerns the future of the UK. If demands for a second Scottish independence referendum gather momentum, or if the difficult situation in Northern Ireland—much aggravated by Brexit—turns into a full-blown crisis that triggers calls for the unification of the island of Ireland, this would probably absorb most of the UK’s political energy for several years. Such developments would deflate the grand foreign policy ambitions announced in the integrated review and, by the same token, reduce the potential for both cooperation and competition with the EU.

There are few people in mainland Europe—apart from supporters of an independent Catalonia—who would welcome a falling apart of the UK, but the EU would find it difficult to keep its distance from such a process. In the case of Northern Ireland, the EU would by necessity be a relevant actor through the management of the Brexit agreement. In the case of Scotland, the EU would be affected indirectly, as the Scottish National Party frames its campaign for independence in terms of Scotland’s return to the EU. Obviously, a disintegration of the UK would force the successor states to fundamentally reevaluate their future relationships with the EU.

A lesser but nonetheless significant development would be a change in government in London. Although the country’s leading opposition figure, the Labour Party’s Keir Starmer, used to be one of the leading voices who called for the UK to remain in the EU, as prime minister, he would be unlikely to take any initiative to reverse Brexit. However, a Labour government under his leadership would probably try to reduce the tensions over the implementation of the Brexit deal and strive for a constructive relationship with the EU. Negotiating structured cooperation in foreign and security policy, as envisaged in the political declaration that accompanied the UK’s withdrawal agreement, would be an obvious opportunity to move beyond the Brexit politics of Starmer’s predecessor.

The EU institutions and member states would undoubtedly welcome such an initiative. Even the idea of a European Security Council could make a comeback. This concept had been promoted by French President Emmanuel Macron and German Chancellor Angela Merkel as a way to keep the UK involved in shaping the EU’s international position, but it was dropped because of a lack of interest from London. Such a body could enable stronger leadership and bring the UK back on board. The challenge is to find a formula that ensures adequate participation of smaller EU members as well.

As for the EU, there can be little doubt that the key factor will be the union’s post-pandemic economic recovery. Foreign policy has always been a peripheral element of European integration. The EU’s ambition and effectiveness depend largely on the dynamism of the core areas. If efforts to restart the European economy are well managed and the 750 billion euro ($890 billion) recovery fund proves its worth as a powerful tool for reform, this should, over time, create new momentum in the area of external policy, too.

Tackling geoeconomic challenges—such as climate policy, digitization and technology, and reforms of the World Trade Organization, areas where the EU already has effective instruments—probably will come first. But eventually, improvements will also be visible in more classical foreign policy. Under such a scenario, the EU could gradually gain the necessary confidence to take the initiative on thorny security issues in its neighborhood. For such efforts to succeed, a close partnership with the UK could make a big difference. Conversely, if the EU’s economic recovery lags behind those of other regions and the pandemic leaves a legacy of divisions and ill will, the current centrifugal tendencies in foreign policy will continue and the potential for EU-UK cooperation will remain limited.


The way in which the UK’s integrated review disregards cooperation with the EU shows that, at this point, the ideological need to distance the UK from its past as an EU member still dominates the thinking in London. The government wishes to justify Brexit as a liberating step, and that stance implies a negative attitude toward the EU. Yet, even during this difficult period, EU-UK foreign policy cooperation will continue on some issues, particularly where there is strong U.S. leadership. On others—especially Asia, trade, or migration—there will be little interest in working together.

Over time, however, once the Brexit disruptions calm down, proximity should reassert itself as the most important uniting factor. There can be no Brexit from geography. The UK may define itself as Global Britain, but it will still be part of Europe. It may dream of the Indo-Pacific, but it will still sit on the edge of the Atlantic. Major shares of the UK’s economic interchange and of its cultural and human contacts will still be with its European neighbors. Many of the challenges the twenty-seven EU member states face in their neighborhood will also be of concern to London. And the two sides’ shared interest in a stable neighborhood should, over time, become a solid basis for a sustained partnership.

The integrated review also shows that the EU and the UK remain closely aligned in their fundamental approaches to global issues. Both support a rules-based international order, effective multilateralism, open societies, and an open and resilient global economy. As many powerful forces are working against these objectives, the EU and the UK will often turn to each other to defend their shared view of the world.

What can the EU do to lay the groundwork for resuming constructive cooperation? Keeping its cool during the current phase of irritation should be the starting point. The constraints on contacts with UK diplomats in response to London’s downgrading of the post of EU ambassador should be overcome rapidly. Cooperation in areas where both sides desire it— such as climate, the JCPOA, and counterterrorism—should be pursued with great energy. Success in these areas will help overcome reticence on other topics. On questions where interests are broadly shared, such as the Western Balkans or Eastern Europe, the two sides should develop informal ways of coordinating policies. And when the time is ripe, the absence of a structured relationship on foreign policy need not prevent high-level contacts. If Blinken can be invited to an EU foreign ministers’ meeting, why not UK Foreign Secretary Dominic Raab?