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Abstract

The European response to Russia’s invasion of Ukraine is characterised by an emerging division-of-labour between NATO and the European Union (EU). By reducing the substitutability of organisational frameworks, this makes life more difficult for outsiders – like the post-Brexit United Kingdom – which find themselves on the outside of key decisions. Drawing on interviews with policymakers, this article shows how Britain has engaged with EU security policy following the Ukraine War. It shows how the EU/NATO division-of-labour undermined the viability of Britain’s post-Brexit break with EU security policy and brought about a concerted effort to engage from the outside, including efforts to lead by example, establish new frameworks, and coordinate through informal channels. The findings help explain how seismic events can shape institutional choice and thus the costs of remaining on the outside, and they showcase the diversity of means available for external engagement.

Keywords

European security European Union institutional choice NATO Ukraine War United Kingdom

Introduction

Russia’s full-scale invasion of Ukraine in February 2022 upended the strategic status quo in Europe. While the conflict has placed NATO’s role as the continent’s primary defence provider more firmly in the spotlight, the actions of the Atlantic alliance have been limited by the spectre of a second Trump administration, the organisation’s narrow focus on traditional defence, and Ukraine’s non-member status. The European Union (EU) has become an increasingly important actor since the invasion, financing and coordinating military aid to Ukraine, working to diversify the continent’s energy supplies, offering Kyiv the prospect of membership, and enacting successive rounds of sanctions on those close to Vladimir Putin’s regime. The combination of changes on the EU side and limitations to NATO’s role have brought about a clearer division-of-labour between the two organisations in which both have become crucial actors in the broader Western response, leading to increasing coordination between the military and civilian sides of Brussels (Hoeffler et al., 2024).

Where does this leave the post-Brexit United Kingdom? Britain left the EU formally on 31 January 2020 following the ratification of the Withdrawal Agreement, fulfilling the pledge of successive Conservative governments to implement the mandate established in the June 2016 referendum. In February 2020 the Johnson government declined to negotiate a security and defence agreement as part of the talks on the future relationship, resulting in the hasty ‘bilateralisation’ of the UK–EU security relationship. The significant involvement of NATO and the EU both in the broader European response to Russia’s war means that the United Kingdom finds itself outside one of the principal decision-making forums. In response, London has sought ways of engaging with the Union from the outside, including both extra-EU engagement with member states and informal engagement with the EU itself.

The central claim in this article is that Britain’s re-engagement with EU security policy from the outside is motivated by the emerging division-of-labour between the EU and NATO in responding to the Ukraine War, which makes outsider status more costly. Drawing on elite interviews conducted with 37 individuals from the United Kingdom and the EU in the years following both the Brexit referendum and the invasion of Ukraine, the article shows how the United Kingdom’s relationship with EU security and defence policy has shifted from divergence towards greater engagement. It shows how the adoption of a distant relationship, borne of the desire to signal a more autonomous post-Brexit relationship, was enabled by the choice of EU and NATO frameworks for coordination and missions. It demonstrates subsequently that the emerging EU/NATO division-of-labour which followed Russia’s invasion made this impractical, leaving the United Kingdom on the outside of a key framework for strategic decisions. And finally, the article charts the United Kingdom’s efforts to re-engage with EU security policy from the outside, including efforts to lead by example, bilateral actions in support of the overall EU line, the creation of new non-EU ties with member states, and informal engagement with EU policymaking.

The article makes several contributions. Empirically, it helps explain why successive governments of the same ideological persuasion sought distinct relationships with EU security policy. It also highlights the impact which a specific aspect of the broader Western effort to defend Ukraine has had on the United Kingdom’s priorities and interests – namely, the shifting politics of institutional choice. And it shows how the United Kingdom has sought to engage productively from the outside, detailing the different approaches adopted while highlighting some of the trade-offs involved in external engagement. Theoretically, the article makes three main contributions. First, it shows that outsider status can be made more difficult by the emergence of institutional divisions-of-labour where this serves to undermine or remove a prior choice of frameworks. Second, it shows that exogenous shocks can alter inter-institutional relations significantly, offering a distinct account of how such moments matter beyond their role in shaping policies and opinions. Third, if offers a systematic appraisal of the ways states respond to situations in which their outsider status leaves them outside the room, discussing the trade-offs involved in different modes of external engagement.

The article proceeds as follows. The first section sets out the necessary conceptual apparatus for understanding the changing politics of institutional choice and the implications for outsiders. The second section discusses the case study of Britain’s re-engagement with EU security following the Ukraine War, showing how events of the period are situated vis-à-vis the core theoretical concepts and detailing the expectations of the analysis. The following sections chart empirically the United Kingdom’s response to the Russian invasion of Ukraine, drawing on the interview data to show how Britain has sought to re-engage with EU partners.

Outsiders and the politics of institutional choice

In the international system, states are incentivised to pool their resources and coordinate with like-minded actors in order to deal with external threats (e.g. Cladi and Locatelli, 2021; Götz, 2019; Rynning, 2011). Security institutions help states to achieve this by providing for reciprocal interaction and confidence-building (e.g. Kydd, 2001; Wendt, 1992), coordinating the actions of individual states (Abbott et al., 2015), reducing transactions costs and sanctioning non-compliance (Abbott and Snidal, 1998; Axelrod and Keohane, 1985), and fostering shared identities and practices (Adler, 2008; Checkel, 2005; Flockhart, 2004; Pouliot, 2008; Schindler and Wille, 2015), Yet the strategic institutional landscape is highly variegated and the presence of multiple organisations in the security and defence realm – with overlapping functions and memberships – is a reality in most regions of the world (Alter and Meunier, 2009). Complex patterns of mutually reinforcing institutions, including global, regional and ‘Western’ examples, have emerged in the post-WWII period (Cottey, 2022; Deudney and Ikenberry, 1999), and these organisations have evolved over time in ways which encroach on one another’s roles (Hofmann, 2011; Pierson, 1996). Such complexity is exacerbated by a range of differences between organisations, which can vary in terms of task exclusivity, degree of centralisation, membership, and geographical coverage (e.g. (Abbott et al., 2000; Hofmann, 2019; Koremenos et al., 2001).

The presence of multiple formats sets the stage for dynamics of institutional choice (e.g. Hofmann, 2011, 2019; Howorth, 2019). Where actors have a choice of substitutable formats, they can engage in forum shopping behaviours (Celik, 2024; Hofmann, 2011), benefit from institutional arbitrage (Ewers-Peters, 2023; Hafner-Burton et al., 2009), and indulge partisan whims more easily (e.g. Hofmann, 2013; Rathbun, 2011), Institutional choice also enables – and in part stems from – the decision of some actors to stay outside of specific organisational frameworks in areas where they maintain a stake in policy outcomes. Outsider status can reflect sovereignty concerns, as with Gaullist opposition to NATO and British opposition to European integration (Hofmann, 2017), as well as deep-seated commitments to principles like neutrality, which preclude membership of military alliances (Cottey, 2013). It can also result from the exclusion of states from institutions on the basis of geographical or cultural criteria, or at the behest of internal veto-players, as was the effective case with Turkey and the EU (Dursun-Özkanca, 2017). While institutional choice is in part a product of the decision of some actors to remain outside specific organisations or to promote alternatives (e.g. Morse and Keohane, 2014), institutional choice also enables states to remain outsiders, since the multiplicity of frameworks provides alternatives to organisations which actors – for whatever reason – are unable to join.

Yet this is only the case where the conditions for a genuine choice of frameworks continue to apply. These conditions are highly specific in practice, and exist as a result of particular configurations of institutional overlap and how these relate to the broader strategic environment. Where overlap exists in the tasks of institutions, actors can afford to treat them as functional substitutes. But where a division-of-labour exists, and institutions perform specific tasks that are not interchangeable, there is little possibility for direct substitution (Celik, 2020; Hofmann, 2011). Rather, in such instances, it becomes necessary to coordinate across multiple institutions as part of an overall multi-actor response (e.g. Abbott et al., 2015; Ewers-Peters, 2021). Whether a choice exists depends partly on how coterminous memberships are. A significant overlap in membership – especially among powerful actors – makes a free choice easier than in situations where the selection of one framework excludes key actors. Moreover, the choice of formats is also influenced by the nature of the strategic environment: The more security issues become entangled with non-security domains (e.g. energy, trade, migration, climate) the more important the task functions of different organisations become in responding to strategic challenges. Finally, the viability of formats also influences the scope for choice, since uncertainty regarding the future of any one institutional option creates hedging dynamics which can be inimical to the selection of one framework over another.

Significant changes in international politics in recent years have undermined some of the dynamics which have historically provided for institutional choice in the security domain, while paradoxically increasing the demand for outsider status. Globalisation and the resulting fragmentation of the international order has increasingly blurred traditional distinctions between domestic and international domains of policy-making (Chryssogelos, 2020; Zürn, 2014) and between traditional and non-traditional security threats (Farrell and Newman, 2019; Hagmann et al., 2018)). The rise of a more multipolar order characterised by the diffusion of power away from the so-called ‘West’ and the resulting rise in geopolitical tension – amid continuing interdependence – has returned defence to the forefront of the policy agenda while broadening the range of tools needed to deter adversaries (Baciu, 2022; Grevi, 2009; Laïdi, 2014). The backlash against globalisation, meanwhile, had fed a rise in global populism, motivated in part by a desire to return control from the supranational level back to the nation-state (Abrahamsen et al., 2020; Destradi et al., 2022; Destradi and Plagemann, 2019; Drolet and Williams, 2018). In the United States, the rise of populism has exacerbated fears of American disengagement from the liberal order in general – and the European security order in particular – undermining institutions whose functioning depends on a stable US commitment (De Orellana and Michelsen, 2019; Friedrichs, 2020). The cumulative effect of these trends is to deny states the ability to make a choice between genuinely substitutable frameworks for security cooperation while increasing the likelihood that key actors will find themselves outside of specific institutional frameworks.

The emergence of institutional divisions-of-labour is problematic for outsiders, since their status excludes them from important components of the overall institutionalised response. Where multiple frameworks are involved in responding to threats, maintaining influence thus requires outsiders to find mechanisms of external engagement. There are several ways in which they can seek to achieve this. First, influence can result from unilateral actions aimed at demonstrating leadership capacities (e.g. as a ‘thought leader’ or ‘first mover’) with a view to cultivating authority and reputational benefits among the membership of other organisations (e.g. Lake, 2010; Weisiger and Yarhi-Milo, 2015). Second, they can engage ‘behind the scenes’ in ways that support the policies and priorities of institutions from the outside through engagement with other countries and institutions – as with forms of ‘differentiated cooperation’ (e.g. Amadio Viceré and Sus, 2023; Howorth, 2019; Klose et al., 2023). Third, they can establish new forms of linkage with countries belonging to institutions they are not a part of, either on a bilateral or multilateral basis, in order to keep conversations going (e.g. Brusenbauch Meislová and Glencross, 2023). Fourth, actors can seek engagement through informal political means, which can include coordination outside official channels, ad hoc meetings, knowledge provision, and personnel exchanges (Mayer, 2011; Shapovalova, 2016). And fifth, they can engage formally with organisations from the outside where opportunities exist for association to specific policy structures for third countries (e.g. Svendsen, 2022).

Engagement from outside can aid coordination, but it can often be more limited than engagement as a member. Outsiders can find themselves as rule takers, able only to support decisions made within institutions but not to shape them, owing to their absence from decision-making structures, a status which is often reinforced by legal and political barriers to external influence over decision-making. Informal cooperation can be highly beneficial, but encounters clear limitations by virtue of being unstructured, including the inability to engage in longer-term strategic thinking, ring-fence issues from immediate political contestation, and establish more specialised working groups (e.g. Westerwinter et al., 2021: 19). The establishment of alternative mechanisms for cooperation with like-minded states can risk the duplication of formats and result in additional complexity and – where multilateral formats are replaced with bilateral ones – increased inefficiency. In addition to these concerns, efforts to establish bespoke ties can risk competitive dynamics which can undermine the overall collective response, insofar as they can directly challenge the institution’s role as the principal interlocutor for its members (Howorth, 2019). Thus, while outsiders can find alternative avenues for influence, these often come with important limitations and trade-offs.

The United Kingdom as a case study

This article examines the impact of institutional choice on outsiders through a detailed study of British engagement with EU security and defence policy after Brexit and the invasion of Ukraine. European security comprises a highly variegated architecture characterised by an interweaved web of multilateral institutions, mini-lateral formats and bilateral relationships, the respective relations between which are in a gradual state of flux (e.g. Celik, 2021; Ewers-Peters, 2023; Flynn, 2023; Hofmann, 2009, 2011; Smith and Gebhard, 2017). Britain’s relationships with these various formats – and especially EU formats – has changed over time, most evidently following the 2016 Brexit referendum, but also following the February 2022 invasion. The presence of variation in the degree of institutional choice over time, and corresponding changes in the United Kingdom’s relationship to EU security issues, presents a prima facie case that factors relating to institutional choice play a significant role in British decision-making in this area.

Britain is not the only case of an outsider facing shifting incentives in response to changing inter-institutional relations. Indeed, in Europe alone many such examples exist, including France’s changing relationship with NATO (Hofmann, 2017), the positioning of Turkey and Norway in relation to EU foreign policy (Svendsen, 2022), and the role of neutral states in the EU and outside NATO (Cottey, 2013). The existence globally of various regime complexes and distinct configurations of memberships amid partially overlapping organisational frameworks means that such dynamics can be found in almost any region of the world (e.g. Alter and Meunier, 2009; Cold-Ravnkilde and Jacobsen, 2020). The reason for focusing on the United Kingdom is that it combines variation in both outsider/insider status and in inter-institutional relations over a relatively short time-period. The British example also allows us to speak to contemporary debates concerning the role of an important geopolitical actor in containing Russian aggression.

The article draws on the findings of 37 semi-structured elite interviews with policymakers in the United Kingdom, the European External Action Service (EEAS) and the foreign ministries of major EU member states conducted between 2022-24. The interviews took place online and involved individuals responsible for the articulation and analysis of European security across the respective actors, including policymakers, diplomats, former officials and think-tank analysts. Interviewees were asked to comment on the response of the United Kingdom, the EU and NATO to the conflict; on the changing EU/NATO relationship and the implications for the United Kingdom; and on the United Kingdom’s relationship to EU security initiatives from the outside. A total of 12 interviews are directly quoted and referenced in the text, with the remainder being utilised for background knowledge of the case, in some instances at the request of the interviewee.

The interview data were transcribed and analysed according to a deductive approach in which the principal dynamics affecting the UK–EU security relationship after the Ukraine War were identified a priori and then traced through the empirical evidence in order to show how these dynamics impacted United Kingdom and EU positions. The analysis backs up the theoretical claim that a lack of institutional choice makes it more costly to be an outsider. While the choice of formats represented by the availability of EU and NATO frameworks for collaboration and joint missions could – prior to February 2022 – make a more distant relationship to EU security policy relatively low-cost for the United Kingdom, the emerging division-of-labour following the Ukraine War has made it more costly for London to be on the outside and has prompted re-engagement as a consequence. The analysis subsequently shows the different means by which the United Kingdom has sought to engage with the EU’s response to the Ukraine War, while noting some of the pitfalls of doing so from the outside.

The remaining sections of the article chart the principal empirical developments in the United Kingdom’s relationship with EU security policy, beginning with a historical overview which draws extensively on existing sources, before detailing the impact of the Brexit referendum and the Ukraine War with reference to the interview data.

Britain and EU security and defence

In the aftermath of the Second World War, the search for a transatlantic security commitment from the United States and the parallel process of economic integration within Europe brought about a division-of-labour between the military NATO alliance and the ‘civilian’ European Community (EC) (Krotz, 2009). The failure of proposals for a European Defence Community (EDC) in 1954 in the French National Assembly reinforced this distinction, keeping the EC on a predominantly civilian path until the late 1990s. While Britain and France both played a significant role in the formation of NATO, the United Kingdom sat on the sidelines as France, West Germany, Italy and the Benelux nations forged ahead with the integration of their economies. Britain’s reticence had to do both with the orientation of its trade towards the Commonwealth and the opposition of the UK coal sector to European integration, as well as the absence of a comprehensive challenge to Britain’s sense of self after the war, having emerged on the winning side. Yet poor economic performance, military overstretch and rapid decolonisation during the 1950s and 1960s motivated a new approach to European integration in the United Kingdom, with membership of the club seen as a means of arresting Britain’s geopolitical decline and bolstering economic productivity (Hill, 2023). After a thorny beginning owing to the rejection of Britain’s first application by French President Charles de Gaulle, the General’s fall from power in April 1969 paved the way for Britain to join the EC on 1 January 1973.

Britain’s accession to the EC coincided with efforts to establish cooperation on political and strategic matters between the member states, owing in part to European concerns at being overly dependent on the US against the backdrop of the Vietnam War. European Political Cooperation (EPC) provided a mechanism for coordinating on foreign policy matters, with six-monthly meetings of the foreign ministers helping to establish a genuine ‘European’ position on key issues, including the CSCE process. The end of the Cold War brought about increased concern about the expectations on Europe as a global actor and the sustainability of the American security commitment, leading to the establishment of more formal mechanisms for cooperation via the new Common Foreign and Security Policy (CFSP) (Hill, 1993). The rise of institutionalised cooperation brought about a gradual Europeanisation of UK foreign policy and helped establish a ‘coordination reflex’ between European capitals (Juncos et al., 2024). Britain’s membership of the EC/EU thus helped London retain a collective voice in global politics amid decline and complemented relationships with other actors, including the United States (Gaskarth and Langdon, 2021: 56). Yet there remained a tension between the United Kingdom’s desire to play a global role and its capability to do so alone (e.g. Blagden, 2019; Hill, 2023; Turner, 2019b), and this reinforced the belief in some quarters that Britain’s role in European integration equated to the acceptance of a more regional role (Hill, 2023).

Fears of European reliance on NATO in the Balkans in the mid-1990s, coupled with the election of a more Europhile Labour government in the United Kingdom in 1997, culminated in a Franco-British push for the establishment of European structures for regional security and crisis management (Hofmann, 2013; Hofmann and Mérand, 2020; Holden, 2011: 159). The first missions under the Common Security and Defence Policy (CSDP) launched in 2003 (Dijkstra, 2012), yet the United Kingdom invested less in the new structure than might have been anticipated, and Blair’s commitment to structures he pushed to establish was ‘lukewarm’ (Holden, 2011: 167). The United Kingdom contributed less to CSDP missions than other member states relative to its size and sought alternative formats for operations and for cooperation on defence matters. The United Kingdom also worked to prevent any developments which would challenge NATO’s role as the principal defence provider on the European continent, limiting the scope and supranational aspects of CSDP (Holden, 2011: 167–169). For the United Kingdom, the CFSP and CSDP and their institutions comprised a ‘useful extra’, allowing for greater flexibility in the choice of formats for low-intensity missions and for conversations on security issues without the United States in the room (Whitman, 2016). EU security structures thus partially encroached on NATO activities, but principally in ways that served US interests, and not in a manner that challenged NATO’s supremacy in continental defence (Sweeney and Winn, 2022).

The Leave vote in the June 2016 Brexit referendum challenged this status quo and forced a reappraisal of the United Kingdom’s priorities and international alignment (Gaskarth and Langdon, 2021: 56). Security and defence issues were scarcely mentioned in the campaign itself (Hill, 2023), but divisions over sovereignty had implications for Britain’s foreign and security policy and its international roles (Beasley et al., 2021; Gibbins, 2022; McCourt, 2021). While both sides in the debate emphasised the need to be ‘global’ and to maintain strong relations with the US and Commonwealth countries, they diverged on whether EU membership was a constraint or an enabler of these (Martill and Rogstad, 2024). Brexit would see the United Kingdom formally depart from EU forums for foreign and security policy cooperation, pushing the United Kingdom to do more through other formats, including the United Nations (Dee and Smith, 2017; Gifkins et al., 2019: 1350) and – within Europe – NATO and existing bilateral and mini-lateral formats (Brusenbauch Meislová and Glencross, 2023; Sweeney and Winn, 2022). Brexit also challenged United Kingdom foreign policy in other ways, forcing the United Kingdom to engage with European partners in the more ‘polycentric’ manner of third-countries rather than being at the table (Whitman, 2019: 385) and making the United Kingdom less useful to transatlantic and Commonwealth allies while simultaneously complicating these existing relationships (Oppermann et al., 2020; Webber, 2023). The referendum also destabilised the constitutional and political status quo, increasing the prospect of Scottish independence and presenting significant budgetary challenges given the overwhelmingly negative implications of Brexit for the UK economy (Blagden, 2017: 9, 11).

Theresa May’s government presented Brexit as an opportunity to become a ‘Global Britain’, a phrase intended to demonstrate that Britain would not withdraw from its international commitments (Webber, 2023) and to construct a narrative of increased global relevance after Brexit (Daddow, 2019; Haugevik and Svendsen, 2023; Turner, 2019a). Under May an attempt was made to pursue a security agreement with the EU, with proposals outlined in May 2018 for an agreement that would see the United Kingdom remain plugged-in to the CFSP/CSDP across various levels (HM Government, 2018). Prospects for continuity in this domain were strong, given the United Kingdom’s status as a military power and the bargaining advantage that resulted, coupled with the lack of significant political constraints in security policy (Blagden, 2017: 13; Svendsen and Adler-Nissen 2019; Turpin, 2019). But the proposals proved unpopular domestically among Brexit supporters and looked set to make the United Kingdom a rule-taker in important areas (Whitman, 2019: 394). For the Johnson government, security cooperation quickly became an area where the United Kingdom could easily maintain a more autonomous relationship from the EU with comparatively little cost, given the existence of NATO and other formats for cooperation with member states (Martill and Mesarovich, 2024). As such, Johnson opted in February 2020 to forego talks on a security agreement, leading to the absence of any structured relationship by the time the United Kingdom left the transition period on 1 January 2021.

The Russian invasion of Ukraine

On 24 February 2022, Russian tanks crossed into Ukraine, beginning the ‘special military operation’ through which President Vladimir Putin hoped to achieve regime-change in Kyiv. The Western response to the invasion, incorporating condemnation of Russia’s actions and support for the Ukrainian war effort – while avoiding escalation into major-power war – had an important role for NATO and the EU both. As the organisation responsible for collective defence and strategy, and for co-opting the military weight of the United States, NATO became the focus of attention following the invasion. Through the Ukraine Contact Group, NATO members worked to coordinate the alliance’s response to the invasion. Political and logistical support for the Kyiv government was pledged and the forward presence in Eastern Europe stepped up with additional troops and increased patrols of the Russian border. Together allies contributed to the transfer of significant levels of military equipment to Ukraine and the disbursement of billions of dollars in financial aid. And, after a lengthy diplomatic back-and-forth, NATO welcomed Sweden and Finland as new members of the alliance, countries that were both sufficiently spooked by Russia’s actions to forego their long-held position of neutrality.

And yet NATO’s role was insufficient as a platform for the entire European response. The nature of the conflict required not only a show of military strength, but political coordination along with economic pressure and diversification, tasks for which NATO – as a military alliance – were not suited (Hill, 2023). After the conflict, the principal task would be economic reconstruction, another area in which NATO neither had the competence nor the ability to marshal the requisite economic capacities. There were also limitations to NATO’s role stemming from the perceived risk of escalation should the alliance become embroiled in a military conflict with Russia, given that Ukraine was not a NATO member (Webber, 2023). And with NATO accession ruled out by Western allies, and by Kyiv itself, conversations about frameworks for post-war security would need to involve other regional institutions. Nor did concern about the long-term stability of the US commitment to Europe and the damage to NATO’s credibility abate, given the approaching election in November 2024 and the growing risk of a second Trump Presidency. All of which meant that, while NATO played a considerable role in the Western response to the conflict – and while mutual NATO membership enabled coordinated action in diffuse ways among European countries – the European response could not operate through NATO alone.

This created political space for the EU to become a more significant strategic actor. Consensus among the member states (Casier, 2023; Laffan, 2023), coupled with a perceived responsibility to act (Maurer et al., 2023), helped enable a growing role for the EU in the response to the invasion (Bosse, 2022; Genschel, 2022; Orenstein, 2023). The EU has thus far committed $47bn to the total war effort through a variety of mechanisms (EEAS, 2024a)¹ and member states have enacted 14 successive sanctions packages targeting individuals and organisations close to the Putin regime (European Council, 2023b). Through the European Peace Facility (EPF), the EU has agreed financing of 12bn euros in lethal and non-lethal aid to Ukraine (European Council, 2023a). Member states established a clearing cell in Brussels through which to coordinate the transfer of military equipment to Ukraine and in October 2022 established EUMAM Ukraine to provide training and assistance to the Ukrainian Armed Forces (EEAS, 2024b). The Strategic Compass, underway when the invasion occurred, was repurposed as a forum for finding common ground on the invasion and the European response (Casier, 2023). Both Ukraine and Moldova were granted ‘candidate country’ status in June 2022, their applications having been fast-tracked in response to the conflict (Anghel and Džankić, 2023; Anghel and Jones, 2024) And, through the REPowerEU initiative of May 2022, the EU intensified efforts to diversify energy supplies away from Russian natural gas (Goldthau and Youngs, 2023).

The EU’s increasing actorness was enabled by the nature of the conflict – its location, its scale, the context of interdependence – and by the unsuitability of NATO formats for some of these tasks, as well as the underlying fragmentation of the liberal international order (Costa and Barbé, 2023). The result was that the European response to Russia’s invasion involved coordinated action through both NATO and EU frameworks, each of which undertook specific tasks in an emerging division-of-labour (Hoeffler et al., 2024). This differed from past allocations of tasks in which both sides could remain largely separate, but it also different from a scenario in which both frameworks could be used to similar ends. Since the response to the crisis required the competences of multiple different institutional frameworks, increased EU-NATO coordination was one important outcome (Casier, 2023). In the words of one EU official, there had been ‘a time when we basically pretended NATO didn’t exist . . . and they pretended we didn’t exist and we couldn’t talk to each other, and we’re really not in that place [now]’ (Interview 1). EU-NATO coordination was also enabled by the increasing convergence in membership brought about by the impending (at the time) accession of Sweden and Finland to NATO (Helwig, 2023: 60), although the departure of the United Kingdom from the EU in 2020 had previously reduced this overlap.

Changes on the EU side have had implications for Britain’s response to the war. Britain’s interest following the invasion was to defend the territorial integrity of Ukraine and prevent events from escalating into a broader conflict (Hill, 2023). Accordingly, under the Johnson government, the United Kingdom made support for Kyiv a priority while warning that direct intervention by NATO was off the cards. Johnson visited Kyiv in April 2022 to offer a show of support to Volodymyr Zelenskyy, and again in June and August of that year. In the months that followed, the United Kingdom committed military equipment to Ukraine, including Challenger tanks, armoured vehicles and helicopters. The United Kingdom was a significant provider of aid to Ukraine, having committed, as of January 2024 £12.7bn in total assistance, including £7.6bn in military aid (House of Commons, 2024: 1). Britain’s robust support for Ukraine was a product of a more hawkish stance on Russia in recent years as well as its strategic culture and willingness to use military force (e.g. Blagden, 2015). In the years preceding the invasion, the United Kingdom had been vocally sceptical, for instance, of Germany’s increasing energy dependence on Russia and of French efforts to broker a détente in East-West relations. While the British (and, arguably, Western) response to the 2014 annexation of Crimea was in hindsight more muted than might have been necessary to deter future aggression, after 2014 the United Kingdom began focusing efforts on building up NATO’s forward presence in Eastern Europe, working with allies in the Joint Expeditionary Force to enhance the naval presence in the Baltic and the North Sea, and providing – through Operational Orbital – training for the Ukrainian Armed Forces (Floyd and Webber, 2024: 1162).

The emerging division-of-labour between NATO and the EU made the United Kingdom’s post-Brexit status as an EU outsider more costly. The British position required that other European countries follow suit and that these efforts be coordinated. Yet Brexit had removed the United Kingdom from one of the principal forums in which key decisions were being made and reduced the likelihood that other European states would look to London for a leadership role (Hill, 2023). On the outside, Britain no-longer benefitted from the coordinating role of go-between which membership of both NATO and the EU provided for (Ewers-Peters, 2022) and lost its ability to shape the direction of EU security policy from the inside (Whitman, 2019: 388). Indeed, Brexit actively contributed to the increase in EU actorness, removing a barrier to further development of EU security and defence policy (Blagden, 2017: 13) and precipitating a range of reforms in this area prior to the invasion (Bérard-Sudreau and Pannier, 2021). These limitations, coupled with evidence of growing EU actorness, contributed to the ‘recognition that actually the EU does really, really matter’ because of ‘the capacity of the EU to amplify and augment the abilities of the member states to do stuff when they’re willing’ (Interview 2). As a result, the United Kingdom has increasingly acknowledged the distinctiveness and significance of the EU position (Interview 3) and has sought greater coordination with the EU in order to ‘get information about what we’re doing on the EU side from the perspective of whatever’s sitting on NATO’s desk’ (Interview 1).

British re-engagement with Europe

Efforts to re-engage with EU member states in recent years have taken several forms. One prominent aspect has been efforts by the United Kingdom to ‘lead by example’. British decisions to send equipment to Ukraine ‘set the tone for the American offers of military equipment’ such that the United Kingdom’s strategic support has been ‘thought leading’, the United Kingdom having ‘offered each one a little bit ahead of our partners . . . each of these things is sort of slightly ahead of where other European partners and even the Americans’ (Interview 3). And ‘you’ve seen others come to the table because of that . . . shifting the Overton window of what the international community is willing to provide’ (Interview 3). In terms of the broader diplomatic response, Britain has sought to play a convening role, ‘leading by example’ and a ‘galvanizing role of just reminding states, particularly in the West of Europe, of the . . . importance of all of this’ (Interview 2). This has been reinforced by the ‘muscle memory’ of the foreign policy community, which when it comes to Europe has always been ‘coordinate, coordinate, coordinate. And that has very much been reactivated as a consequence of Ukraine’ (Interview 2). The upshot is that the United Kingdom ‘has been very involved in the discussions that it should have been involved with and . . . that’s a nice alternative to having been basically kind of outside and side-lined for much of the previous few years’ (Interview 2).

Despite years of tumultuous relations, the European response to United Kingdom actions was positive, such that Britain was able to re-capture some of the respect lost as a result of Brexit. The United Kingdom was ‘quicker in realising what has happened than others and they pushed us in the right direction . . . the war on Ukraine, as terrible as it sounds, has really helped the UK reputation abroad’ (Interview 4). In the words of one European official,

the British attitude towards Russia [and] Ukraine in the aftermath of the invasion, which I think has been incredibly strong, direct and very much appreciated, not just by the Ukrainians, but also by Eastern Europe [and] by most of the EU. (Interview 5)

Another member state official noted that they appreciated

the added value of closer cooperation [on] security because the UK is a nuclear state, because the UK has a strong army, because the UK is important . . . for European security’, continuing that ‘the war in Ukraine basically just showed that they are indeed militarily very capable. (Interview 6)

For the EU institutions, the invasion raised ‘awareness that we have to work together’ (Interview 7) and a realisation that ‘we share the same interests and values, so there’s been a . . . natural need to speak more’ (Interview 8). The changing geopolitical context therefore, made ‘it more of a necessity to cooperation with the UK instead of cooperation being a ‘nice to have’’ (Interview 9).

The United Kingdom also sought to engage with EU member states via non-EU institutional arrangements (e.g. Reykers and Rieker, 2024). For instance, bilateral engagement with core member states was stepped up, with a host of declarations and joint statements following the invasion (Brusenbauch Meislová and Glencross, 2023). While bilateral and pluri-lateral arrangements represent ‘quite a natural place for the UK’, the ‘sense of urgency has meant that ad hoc coordination has been established’ (Interview 5). In May 2022 the United Kingdom agreed ‘mutual solidarity’ agreements with Finland and Sweden, guaranteeing their security prior to their expected accession to NATO. The United Kingdom also ‘worked very carefully and closely with European partners in convincing Turkey and Hungary that Sweden and Finland should be admitted’, offering ‘the sort of diplomatic heavy lifting’ (Interview 3). Through the Joint Expeditionary Force (JEF) the United Kingdom has ramped up its naval operations in the North and Baltic Seas, including with many current EU member states. And London has expanded its UK-based training mission for the Ukrainian Armed Forces, establishing the multi-national Operation Interflex training programme in June 2022, training 30,000 Ukrainian soldiers.

And London has sought to coordinate with European partners within NATO and the G7. After Brexit, ‘NATO became an alternative forum and platform’ (Interview 2), but the United Kingdom has also been aware of the limitations of a NATO-only approach, and has actively sought to coordinate with the EU where its competences impinge on NATO discussions (Interview 1). The aim of United Kingdom thinking has been: ‘How do we make sure that the European caucus within NATO is effective?’ (Interview 2). The United Kingdom thus

tries to avoid the sense of . . . These are NATO’s objectives. These are bilateral objectives. These are EU objectives. What we see is a greater lattice of interrelationship between all of those. And we walk crab like along the different streams of activity in order to bring relationships forward bit by bit. (Interview 3)

The G7 has also been an important forum for cooperation, especially while the United Kingdom held the Presidency in 2021. One EU official pointed out the significance of ‘this overall G7 cooperation taking place, where we strategized on how to approach Russia and Ukraine related initiatives in multilateral for a, how to coordinate better on our [global] outreach’ (Interview 10). Yet member states also cautioned that these forums could not substitute for EU issues, and there was some resentment against the United Kingdom trying to raise issues pertaining to sanctions in non-EU forums (Interview 4).

The Johnson government also began a gradual process of re-engaging informally with the EU. UK Foreign Secretary, Liz Truss, attended an extraordinary meeting of the EU’s Foreign Affairs Council, to discuss the Western response, while Johnson and Commission President von der Leyen spoke on the phone following the invasion. The United Kingdom and EU also coordinated on sanctions, with the United Kingdom effectively aligning with the Council’s agreed position after deliberations, such that the ‘sanctions packages are now quite aligned’ (Interview 7). British military officials were also given a role in the EU’s Brussels-based clearing house call to ‘help channel the donations and offers of equipment to Ukraine’ (Interview 1). Early discussions also occurred between officials at this stage regarding Britain’s potential accession to the Military Mobility project, part of the EU’s Permanent Structured Cooperation (PESCO) initiative. As one EU official described it:

There’s a lot of exchange at the operational level with the UK about wat they’re doing to make sure that we’re pulling in the same direction . . . There’s quite a lot of exchange, but it’s very much ad hoc, issues driven and very much on the basis that there’s an avoidance of anything that looks like entangling alliances. (Interview 1)

Unlike bilateral engagement, informal EU cooperation was simpler, with ‘one big player to engage with on a number of these questions’, rather than multiple, separate engagements with France, Germany, Spain, Italy and other major players (Interview 2).

The EU was more open to engagement with the United Kingdom after Ukraine than in the immediate aftermath of Brexit. The fact that Russia’s aggression ‘challenge[d] the overall European security architecture . . . really facilitated the UK’s active outreach towards us [the EU] and we were happy to receive them and then start to discuss what we can do together’ (Interview 10). As one member state representative, speaking about the UK–EU relationship, noted that ‘If you ask me today, you will get a different answer to the one that you would asking me before Ukraine’ (Interview 11). Yet the feeling was mutual, since ‘the UK was also able to see the added value of closer cooperation within the EU’, which helped make ‘the taboo in cooperation with the EU disappear a bit’ (Interview 9). This also contributed to a shift in the political discourse, with political actors in the United Kingdom moderating their rhetoric and seeking fewer opportunities to demonise the EU in domestic debates (Interview 10). Re-engaging with the EU was made easier on the British side by the practical nature of much of the informal cooperation, which was ‘pragmatic and practical’ and focused on the getting ‘Ukraine back on its feet once the war is over’, leading to a ‘sense of relief that we can get back to doing stuff’ (Interview 2).

The relationship was not unproblematic, however. European leaders found it difficult to deal with Johnson, with whom there had been ‘a fundamental breakdown of trust’, such that he ‘could have promised them everything they wanted and there would not have been an agreement’ (Interview 2). Even after the invasion of Ukraine, officials on the EU side noted a continued ‘tendency to divert attention away from those domestic problems . . . [by] ramping up their fight with the EU, and this has completely diminished all trust in the UK’ (Interview 9). There was also irritation that the UK government’s narrative of leadership deliberately sought to downplay the EU’s role. This included opprobrium regarding the United Kingdom’s tendency to keep cooperation with the EU under the radar and refer instead to European ‘friends and partners’ rather than mention the Union in documents. ‘I really think the UK contribution is important and is significant’, noted one official, ‘but it doesn’t look so outstanding when you say that everybody else is basically doing the same’ (Interview 1). UK officials also found themselves rebuffed when they attempted to feed into EU decision-making informally, and

needed a bit of time in the beginning [due to] the realisation that the UK is no longer sitting at the table so they can only be brought into the Brussels machine after the sanctions have been discussed among the 27 member states. (Interview 7)

Hangovers from the Brexit process – especially regarding the United Kingdom’s failure to implement the Northern Ireland Protocol and honour the Withdrawal Agreement – also conspired to make cooperation more difficult. The EU did not wish to ‘divorce our cooperation or our potential cooperation in this sphere from the broader pattern of the overall strategic relationship between the UK and the European Union’, since it was ‘no great secret that the divorce settlement hasn’t really been fully worked out yet’ (Interview 1). While overall the ‘crisis relationship has been, I think, pretty good and has worked quite well’, in the longer term ‘you need to know that your counterparts are going to be allowed to speak to you . . . time and again [and] we’re not quite in that place’ (Interview 1). While it was welcomed that the United Kingdom was

very active, also initiating a lot of meetings, a lot of discussions, proposing numerous initiatives, we have to always really balance it out and look at all that in the overall context of our relationship, where we are actively proceeding with several infringement procedures against the UK. (Interview 10)

Meanwhile, the EEAS worried that the United Kingdom’s decision to bilateralise its relations with the member states risked undercutting the common EU line, and sought to limit occasions where this might undermine the collective Union position. Officials noted the ‘initial rush to have bilateral strategic agreements with the UK that we tried to map as well as to understand what was going on’, but found that the Protocol succeeded in precluding efforts by member states to stray from the common line (Interview 8). Overall, since they ‘do not want the UK leveraging and exploiting any EU interests against us, we [the EU] remain unified and coordinated’ (Interview 10).

Building bridges: Johnson’s successors

Johnson’s departure in the wake of the ‘Partygate’ scandal precipitated a leadership race within the Conservative Party. Both Chancellor Rishi Sunak and Foreign Secretary Liz Truss put themselves forward for the role, with Truss seen as the more right-wing candidate both in terms of her pledge to up-end the Northern Ireland Protocol (by triggering Article 16) and her commitment to lowering taxes. Yet neither candidate sought to depart from their predecessor’s stance on Ukraine, an issue on which there was little or no dissent from within the broader party or its cadre of MPs. In line with polling, Truss received the most votes from members, becoming Prime Minister and leader of the Conservative Party on 6 September 2022. In the end, Truss would remain in office only 49 days, the market response to the ‘mini budget’ of 23 September leading to the Prime Minister’s resignation and the installation of her former leadership rival, Sunak, as leader. During her brief tenure in Number Ten, Truss committed to continuing Johnson’s staunch support for Ukraine and also to increasing the share of the UK budget allocated to defence, with a pledge to increase spending to 3% of GDP by 2030, a significant increase of almost 50% of the budget at the time (Reuters, 2022). Truss also kept in place Ben Wallace as Defence Secretary, a key Johnson ally who had supported a strong UK response to Russia’s invasion, boosting the continuity between the governments.

Truss presided over a cautious reset of political relations with European allies, especially France, reacting with cautious optimism to French President Emmanuel Macron’s European Political Community (EPC) initiative, even offering to host one of the summits. The decision ‘to go to the European Community . . . improved the relationship with France in particular, and behind the scenes at that stage, we were making progress quite seriously’ (Interview 3). Truss’s declining to trigger Article 16 as suggested during the campaign also helped reduce potential tensions in the relationship with EU member states. Britain’s accession to the Military Mobility PESCO project was confirmed during Truss’s tenure and UK officials during this period worked with EU counterparts to help shape the curriculum for the EUMAM UA training mission. United Kingdom accession to PESCO was a ‘very positive signal, first of all of the UK being interested, but also [as a] very positive indicator from the European Union side that we want to work with the UK in a very close way’ (Interview 1). While European leaders remained wary and uncertain of the new prime minister’s intentions, there was a general appreciation of the new political mood music. In the words of one member state official, the United Kingdom’s status ‘did take a battering in the first years after Brexit and among the diplomats, especially during the Boris Johnson period, there’s no question about that. And now it is recovering’ (Interview 11).

Sunak, upon taking office, strengthened the position established initially by Johnson and continued under Truss. Statements emphasised the United Kingdom’s strong support for the government in Kyiv and the frequency of Sunak’s personal visits to Ukraine – in November 2022 and in February and May 2023 – was similar to Johnson’s. Wallace was retained as defence minister until the Autumn 2023 reshuffle and Sunak maintained the Johnson-era commitment to increasing defence spending to 2.5% of GDP, pending the publication of the Integrated Review Refresh in March 2023. The Review, the first strategic document issued by the United Kingdom since the Russian invasion, set out to systematise the strategic thinking from the earlier 2021 review in light of the Russian invasion. Sunak committed in February 2023 to sending long-range precision missiles to the Ukrainian government and in May 2023 to establishing a training programme for Ukrainian pilots, although he stopped short of committing combat aircraft, pledging instead to build support for a ‘fighter jet coalition’ (Politico, 2023). While support for Ukraine was not subject to contestation within Conservative ranks, Johnson continued to lobby his successor to maintain steadfast support and engaged in his own public diplomatic activities, including visiting Zelenskyy in January 2023.

Sunak also continued the reset in political relations begun under his immediate predecessor. While his ‘underlying attitude to the EU and integration may not be any different – if anything he’s probably more hard-line than Johnson – the fact is he’s regarded as someone that the European Union could do business with and that they trust’ (Interview 2). European officials also saw Sunak as ‘more integrated’, with the new Prime Minister emphasising that ‘we are now setting the stage for a very long war in which everybody understands there has to be more unity’ (Interview 4). Quiet diplomacy between the UK government and the Commission brought about agreement on the Windsor Framework, which was unveiled to UK stakeholders in February 2023 and adopted on 24 March. While relations were improving in any case, the renewed emphasis on political leadership and the improvement in bilateral relationships with the member states, especially France, also ‘create[d] the space for better deal making with EU partners as well’, and was not incidental to the breakthrough on the Irish border (Interview 3). Sunak also ceased using the Global Britain phraseology of his predecessor, which – while considered largely as inward-facing rhetoric by many in Europe – also signalled a move away from the kind of grandstanding associated with Johnson’s approach to foreign policy (Interview 4).

The signing of the Windsor Framework ushered in a more positive political relationship between the United Kingdom and the EU and facilitated intensified collaboration on UK–EU security and defence initiatives (Financial Times, 2023a). The agreement ‘concluded the most acute sore in the relationship between the UK and the EU and its member states, and that allowed us to unlock a huge range of different areas of both bilateral and institutional cooperation’ (Interview 3). Since by this point most of the set-piece and novel forms of cooperation had been set in motion, the principal difference was a qualitative shift in the level of cooperation between officials. Cooperation between the UK-led Interflex and EUMAM UA have continued, as has coordination on sanctions. The United Kingdom was also a significant behind the scenes player in efforts to pave the way for Sweden’s NATO accession, which was delayed by opposition from Ankara (Interview 3). Meanwhile, both sides have continued to exchange notes to coordinate their positions in relation to the Global South, where active efforts to court governments into backing the broader European line are underway. And yet divisions within the Conservatives remain and Sunak opposed proposals for a more formal, structured arrangement for the foreign and security policy relationship – in the form of a ‘Strategic Partnership’ – on the grounds it would incur the opposition of pro-Brexit backbenchers (Financial Times, 2023b). EU officials noted in the United Kingdom there ‘is still a rather strong feeling against doing anything structured and visible’ (Interview 10).

UK officials at the time questioned the ‘need [for] formal structures and institutions when things seem to be doing alright at the moment’ (Interview 2) and noted that there is much that can be done informally to improve cooperation, which appears in any case to be the current direction of travel (Interview 3). Yet there is also a perception among officials on both sides that structured cooperation would also be valuable if it were politically feasible. Even minimally structured arrangements, like summit meetings, would ‘help us weather spats and bumps in the road, of which there are bound to be more to come’, and would allow for a greater emphasis on future planning, since both sides are ‘still in quite a reactive mode’ (Interview 2). EU officials echo these comments, arguing for ‘a certain amount of machinery underpinning the high-level political process if you want to make something reasonably sustainable’ (Interview 1). While sections of the Conservative party remain ideologically opposed to structured cooperation, the Labour Party – in power since the 4 July 2024 general election – has proposed more formal arrangements (Chatham House, 2023). For Labour, such a proposal offers a way to repair the relationship with the EU without encountering backbench opposition or re-opening difficult conversations surrounding the United Kingdom’s relationship to the Single Market or Customs Union (Interview 12).

Conclusion

This article has argued that the reduction of institutional choice prompted by exogenous developments can make life more difficult for outsiders, forcing the adoption of strategies of external influence. Drawing on a series of semi-structured interviews with policymakers in the United Kingdom and the EU, it showed how the United Kingdom’s adoption of a more distant relationship from EU security and defence was enabled by the presence of multiple frameworks for security cooperation and how the emergence of a clearer division-of-labour between the EU and NATO after the invasion of Ukraine made it more costly for Britain to remain on the outside. The result has been the adoption of various strategies aimed at engaging with member states from the outside, including efforts to lead by example and pursue aims coterminous with the EU bilaterally, extra-EU engagement with the member states, and informal engagement with the EU institutions. Such external engagement has not been costless, however, and the United Kingdom has had to gradually adapt itself to the EU’s significant role in the conflict, utilise means that are less efficient than direct engagement, and forego the potential benefits of a more structured relationship.

The study helps us understand important recent developments in European security. It shows how the Ukraine War has changed institutional relations on the European continent and the consequence this has had from outsiders of both the EU and NATO, including making coordination for difficult for the United Kingdom. While it is well known that the invasion represented a watershed moment for public opinion in many states (Blumenau, 2022; Bunde, 2022; De Vries, 2023; Mader et al., 2024), the impact on inter-institutional relations and the consequences of these have been comparatively under-studied. The study also helps us understand UK decision-making, especially the rapid shift from autonomy during the negotiations on the future relationship to re-engagement after the invasion of Ukraine and the corresponding (and significant) changes on the EU side. While the United Kingdom could hope (optimistically) prior to the invasion to shift cooperation with members states into alternative formats, after 2022 this was never going to be possible, effectively leaving no choice but to seek informal re-engagement. The findings demonstrate the range of different ways the United Kingdom has sought to re-engage, including ad hoc and informal coordination, participation in EU programmes, diplomatic support for the European line in global forums, and the intensification of ties with key member states.

What does this mean for the future? The previous Conservative government opposed more structured forms of cooperation, feeling this would be unacceptable to pro-Brexit backbenchers, and focused as a result on increasing informal ties. In contrast, the Labour government – elected by a landslide in the general election on 4 July 2024 – has made a security agreement with the EU a priority, making it likely a formal agreement will be signed in the near future. While the move to a more structured relationship would allow for an intensification of contacts with the EU and a strengthening of relations, it will be no panacea. Informal coordination has worked reasonably well according to officials from both sides, and there will be continued reticence from the EU side to concede UK influence in decision-making even in a more formalised relationship. Thus, the United Kingdom looks set to be engaging from the outside for the foreseeable future, regardless of any agreement on a security partnership. This is likely to be reinforced by developments outside the Europeans’ control. Should a second Trump administration materialise in the November 2024 US elections, and should Russia continue to receive the (informal) backing of powerful states like China, the EU’s role in security provision for the continent is likely only to grow.

Theoretically, the study contributes to a number of debates in International Relations and the politics of foreign policy. First, it contributes to literature on institutional choice by showing how seismic events – such as the onset of war – can act not only as critical junctures, but can also shape inter-institutional relations in complex ways. This provides a novel perspective on such events compared to the existing emphasis on seeing such shocks as ‘critical junctures’ or ‘windows of opportunity’ (e.g. Capoccia and Keleman, 2007; Pierson, 2000). Second, it shows how changes in institutional overlap can influence the roles and strategies of outsiders. While much research on institutional choice looks at the actions of states in multiple organisations, the findings show these dynamics can also influence those on the outside and shape the strategies they adopt. It also highlights the limitations of efforts to directly shape institutional choice, e.g. by promoting one option over others, since this cannot account for future shocks and developments. Third, the findings speak to current controversies in European integration and contemporary UK–EU relations. They show, for instance, how the post-Brexit United Kingdom cannot avoid the need to engage with the EU in areas where Union actorness matters, thereby reinforcing claims that the United Kingdom will be subject to ‘orbiting Europeanisation’ in many domains (e.g. McGowan, 2023).

The study also has two significant implications for policymakers involved in the formulation of national and collective security policies. One lesson is that while the availability of a choice of institutions may offer tempting prospects for disengagement – especially where popular opinion supports this – such strategies are risky. As well as being hostage to fortune and being subject to the whim of external events, which may lead to a change circumstances, departing actors also forfeit the right to shape institutional responses to crises. As the Brexit example shows, UK withdrawal not only became more of a problem once Russia invaded Ukraine, but also meant that London had no say over EU policies at a critical moment. The second lesson is that these kinds of issues are likely to become more prominent as the tensions stemming from decades of globalisation become more evident. While conflict in a globalised world requires a multitude of tools – strategic, economic, societal – to deal with emergent threats and therefore puts a premium on inter-organisational cooperation and orchestration, the blowback from globalisation has itself produced strong demands to ‘take back control’. Acknowledging the benefits of being present in multiple institutional formats – and resisting the temptation to transpose disaffection with globalisation into specific institutions – will be important for avoiding situations in which future influence is hampered by outsider status.

Footnotes

Acknowledgements

I would like to thank two anonymous referees for their helpful suggestions as well as Falk Ostermann, Monika Sus and Adam Holesch for comments on an earlier draft. I am grateful to Alexander Mesarovich for research assistance and to my interviewees for taking time out of their busy schedules.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This article has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 962533.

ORCID iD

Benjamin Martill

List of interviews

Interview 1 EEAS official, October 2022

Interview 2 UK government official, October 2023

Interview 3 Senior UK government official, October 2023

Interview 4 EU member state diplomat in London, October 2022

Interview 5 European diplomat in London, October 2023

Interview 6 EU diplomat, October 2022

Interview 7 Senior EU diplomat, October 2022

Interview 8 Senior EU diplomat, October 2022

Interview 9 Member state government official, December 2022

Interview 10 EU official, May 2023

Interview 11 Member state diplomat in London, August 2023

Interview 12 Former senior EU official, November 2022

Notes

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Return to Europe? Institutional choice,outsider status,and Britain’s response to the Ukraine War

Abstract

Keywords

Introduction

Outsiders and the politics of institutional choice

The United Kingdom as a case study

Britain and EU security and defence

The Russian invasion of Ukraine

British re-engagement with Europe

Building bridges: Johnson’s successors

Conclusion

Footnotes

Acknowledgements

Funding

ORCID iD

List of interviews

Notes

References