‘Crossing the Rubicon’: Explaining Sweden’s decision to join NATO

Abstract

In May 2022, Sweden took the historic decision to apply for NATO membership, thereby ending two-hundred years of neutrality and military non-alignment. How can we explain such a dramatic change in Swedish foreign policy? Although Russia’s invasion of Ukraine constitutes a critical juncture for Sweden and Europe, Swedish neutrality and non-alignment has survived other eruptions of major interstate war in Europe. In this article, we argue the Swedish decision to join NATO represented the ‘tipping point’ of a long and incremental process of change in Swedish security policy. Our analysis utilises a neoclassical realist framework which focuses on examining interlinkages between systemic change and unit-level factors. We conclude that in the case of Sweden, exogenous systemic pressures created a critical juncture, but policy change was only possible because of far-reaching transformations of Swedish foreign policy role conceptions and strategic culture, along with the critical role played by policy entrepreneurs in crisis decision-making.

Introduction

This article seeks to explain Sweden’s response to Russia’s invasion of Ukraine, focusing on the country’s application to join NATO. This decision formally ended 200 years of neutrality and military non-alignment – policies which were deeply ingrained in its identity and strategic culture. As part of a Special Section, our analysis draws upon theoretical insights from Neo-Classical Realism and Foreign Policy Analysis. In doing so, we aim to integrate unit-level intervening variables into a structural analysis to elucidate the interaction between systemic forces and unit-level attributes (Martill and Sus, 2024).

Much of the existing scholarly literature on Sweden’s decision to join NATO focuses on unit level attributes and social constructivist inspired theories (Brommesson et al., 2024; Hagström, 2021; Lundqvist, 2022; Michalski et al., 2024; Thorhallsson and Vidal, 2024). We argue that foreign policy behaviour is inherently complex to explain theoretically because it takes place ‘at the hinge of domestic politics and international relations’ (Hill, 2003: 3) and encompasses multiple actors and levels of analysis (Aran et al., 2021; Carlsnaes, 1993; Gustavsson, 1999; Welch, 2005). We contribute to the existing literature with a more wholistic but theoretically articulated analysis that incorporates both exogenous and endogenous factors, as well as discursive and material factors. In doing so, we align with recent scholarship stressing the ‘historical turn’ in Neo-classical realism which investigates ‘increasingly blurry paradigmatic boundaries’ and which ‘allows for a dialog characterised less by epistemological posturing or enforced synthesis, and more by inter-paradigmatic and even interdisciplinary collaboration’ (Meibauer, 2023, 361). As with the other contributions to this Special Issue, we employ analytical eclecticism (Sil and Katzenstein, 2010) to capture the multivariate and multi-level nature of foreign policy change (see also, Blavoukos and Bourantonis, 2014).

The article proceeds as followed. We begin by specifying our analytical framework, which is drawn from Neo-Classical Realism and Foreign Policy Analysis, but which we develop by specifying intervening unit-level variables that are more attuned to explaining foreign policy change. This theoretical model is then utilised to structure our empirical analysis of Sweden’s decision to join NATO. We conclude by evaluating the nature and significance of the change we have analysed and reflect on the theoretical implications of our empirical findings.

Neo-classical realism and foreign policy change

Scholarly work on Neo-Classical Realist theory has grown significantly over the last two decades (Barkin, 2020; Cladi and Locatelli, 2021; Meibauer et al., 2021; Dyson, 2010; Götz, 2019; Hyde-Price, 2013; Kitchen, 2010; Narizny, 2017; Rathbun, 2008; Tang, 2009; Turpin, 2019). Combined with theoretical insights from Foreign Policy Analysis, it provides a tool of great analytical utility for analysing foreign and security policy (Martill and Sus, 2024). It integrates an analysis of the structural dynamics of the international system with a more fine-grained and multivariable analysis of domestic politics, thereby opening the ‘black box’ of foreign policy making (Lobell et al., 2009; Ripsman et al., 2016). Neoclassical Realism’s central argument is that the primary driver of state behaviour in an anarchical society is the pressures of the international system, but that foreign policy outcomes are only explicable by analysing ‘how systemic pressures are translated through unit-level intervening variables such as a decision-makers’ perceptions and domestic state structures’ (Rose, 1998: 152).

We contribute to neo-classical realist theory by drawing on the ontology of Critical Realism and the ‘structural-relational’ approach (Bhaskar, 2008; Jessop, 1990: 260–270, 2008; Patomäki and Wight, 2000). In line with this ontological approach, we conceptualise states as ‘situated actors’ operating in a ‘strategically selective context’ (Hay, 2002: 126–134; Patomäki and Wight, 2000: 213–238). The structural context is not deterministic, but is ‘strategically selective’, in that it rewards certain strategies and punishes others. The external environment ‘predisposes the choices of leaders and the behaviour of states in certain directions and discourages others’ (MacFarlane, 1999: 251). The international system thus provides a powerful set of structural pressures that socialise states into their foreign policies ‘roles’ (Thies, 2013). As ‘situated actors’, states are conscious, reflexive, and strategic actors, operating in a structured context which favours certain actions over others as a means of realising preferences. Over time, systemically structured outcomes emerge as actors learn how best to pursue their preferences, encouraging states to acquire distinctive foreign policy ‘roles’. These reflect historically constructed routinised patterns of behaviour but remain susceptible to disruption during crises or transformative events. Systemic pressures therefore do not determine state behaviour, they shape and shove it.

In line with the Special Issue (Martill and Sus, 2024), we draw on three explanatory factors distilled from Neo-Classical Realism and Foreign Policy Analysis, which we refine so that they are more clearly tailored to our specific object of study. These are as follows: (1) Geopolitics and systemic pressures, which we argue serve as the primary drivers of foreign policy behaviour. (2) Foreign policy role theory and strategic culture, that is, the ideational factors shaping foreign policy behaviour over time; and finally (3) Party politics and policy entrepreneurs. Here we examine both state institutions and party politics within which foreign policy is formulated and implemented, as well as the role of policy entrepreneurs in crisis decision-making process, when normal politics, established foreign policy traditions and standard operating procedures are replaced by more fluid and transformative processes of decision-making. Crises often serve as inflection points, disrupting established routines and forcing actors to confront new realities. Decision-making under crisis conditions is characterised by heightened uncertainty, urgency, and the potential for transformative change, as traditional constraints – such as foreign policy traditions and standard operating procedures – may be temporarily suspended (Boin et al., 2005). The case of Sweden’s NATO application exemplifies these complex dynamics, illustrating how exogenous pressures, domestic politics, and historical legacies intersect to produce significant policy shifts.

By linking these factors in a sequenced and integrated account, we demonstrate how foreign policy evolves in response to the interplay between structural incentives and domestic mediators, while also accounting for moments of significant change during crises or critical junctures. Our analysis therefore moves from a study of the broader structural and ideational factors shaping a foreign policy tradition to a more fine-grained analysis of domestic politics, before focusing in on critical junctures when policy entrepreneurs have a window of opportunity for transformative change.

Geopolitics and systemic pressures

Systemic pressures form the foundational driver of foreign policy behaviour. The international system, through its geopolitical structure and distribution of power, creates a set of incentives and constraints that reward certain actions while discouraging others. We argue that a Neo-Classical Realist analysis of the external factors of a state’s foreign policy involves a fine-grained, geopolitical analysis of the regional power balance, identifying linkages and constructing spatial frameworks that include interacting political power units (Cohen, 2003). Geopolitics – which we define as the spatial distribution and political institutionalisation of relative power capabilities – involves not just the study of geography but also of technology, given that the significance of geographical features is dependent on the technological capabilities of the age, particularly in terms of transportation and communication, but also military technology (Deudney, 2000: 89). Thus, as Nicholas John Spykman (1938: 29) has argued, the

full meaning of a given location can be obtained only by considering the specific area in relations to two systems of reference: a geographic system of reference from which we derive the facts of location, and a historical system of reference by which we evaluate those facts.

However, systemic pressures alone are insufficient to explain foreign policy outcomes (Gustavsson, 1999; Hyde-Price, 2013). While they establish the ‘strategic selectivity’ of the international environment, the translation of these pressures into specific policies depends on domestic-level variables. Pressures for change will not necessarily lead to policy changes, and hence we need to include intervening variables that explain how changes do or not emerge at the domestic level. Theorising foreign policy change is thus Janus-faced; it also involves consideration of factors inhibiting change and reinforcing foreign policy stability in face of systemic pressures (Goldmann, 1988; Rosati, 1994).

Foreign policy roles and strategic culture

Over recent decades, considerable attention has been focused on the role of ideational factors associated with norms, culture and identity in the formulation of foreign policy. This is reflected in the substantial literature on Swedish foreign policy that draws on constructivist perspectives of identity, role and strategic culture (Bergman, 2004; Doeser, 2016; Hagström, 2021; Michalski et al., 2024). Our analysis focuses on Sweden’s foreign policy roles and its strategic culture which we situate within a neo-classical realist framework. These two concepts capture the key ideational and normative dimensions of foreign policy, which evolve gradually over time and shape how states interpret systemic pressures. Classical realism has long engaged with these concepts, and there is a growing scholarly literature on the overlap and potential synergies between constructivism and neo-classic realism which we contribute to (Barkin, 2003, 2020; Guzzini, 2004; Jackson et al., 2004; Meibauer, 2020; Sterling-Folker, 2002).

We argue that roles and strategic culture do not ‘float free’, but are embedded in institutions, articulated by actors and manifested in practice. The ideational and the material can be distinguished analytically, but ‘it is important that an analytical strategy does not set into an ontological dualism’. The discursive and ideational ‘is only ever relatively autonomous of the material’; ‘Just as structure and agents do not exist in isolation, so too the material and the ideational are complexly interwoven and mutually interdependent’ (Colin Hay, quoted in Jessop, 2008: 48–49). By moving beyond the ontological dualism of constructivism and structural realism, we aim to refine the study of foreign policy role change and to account for the conditions under which roles evolve in response to geopolitical transformations, crises, and domestic political reconfigurations.

Role theory underscores action as purposeful (strategic) and shaped by structural influences (Barnett, 1999; Breuning, 2024; Thies, 2010). Roles represent the codification and rationalisation by states as ‘situated actors’ of their routinised responses to the ‘strategic selectivity’ of the international system over time. They thereby provide a conceptual roadmap of what policy-makers regard as appropriate foreign policy behaviour (Thies, 2013) and of the functions ‘their state should perform on a continuing basis in the international system’ (Holsti, 1970: 245–246). Over time, these domestic perspectives give rise to a series of foreign policy ‘roles’, that together form a distinct foreign policy ‘role set’ (Aggestam, 2006).

Role conceptions provide the conceptual ‘grooves’ within which foreign policy activity takes place and shape policymakers’ responses to new situations and developments. They are more specific than ‘orientation’ but broader than particular programmes of action (Aggestam, 2004: 6). Role conceptions are shaped by cultural, normative, and ideological factors, and constitute the accumulated sediment generated by patterned behaviour that is the result of a long and constant exposure to systemic pressures. Roles serve to consolidate traditions of foreign policy behaviour, giving decision-makers a sense of the values and interests underpinning their day-to-day activities (Thies and Breuning, 2012). Once formed, these sediments can harden over time and endure – even if the material and structural conditions which gave rise to them change. Role conceptions can thus cause a delay in responses to changing material conditions and give rise to ‘cognitive dissonance’ (Breuning and Pechenina, 2020). Role conflict can also emerge due to a contradiction between two or more role conceptions within a country’s role set (Wehner and Thies, 2014).

Nested within foreign policy roles, strategic culture serves as the ‘software’ that underpins a state’s security and defence policy-making (Gray, 1999; Katzenstein, 1996; Lock, 2017). It rests on a specific understanding of the nature of war and conflict, and consists ‘of shared beliefs, norms and ideas within a given society that generate specific expectations about the respective community’s preferences and actions in security and defence policy’ (Heiko et al., 2013: 12). Like foreign policy role conceptions, it is historically derived and codified by situated agents in a strategically selective context, and changes slowly over time through a continual process of self-reflexive evolution and adaptation to the external environment.

Both foreign policy roles and strategic culture are constantly contested, and subcultures and subordinate discourses tend to form embodying rival conceptions (Cantir and Kaarbo, 2012). They persist over time but when material circumstances change significantly, cultural dissonance can emerge. This in turn ‘can be expected to open a window of opportunity that policy entrepreneurs might use to reinterpret or redefine the underpinning norms’ (Heiko et al., 2013: 12–13). In these critical junctures or ‘crisis moments’, policy entrepreneurs have greater scope for reinterpreting or redefining some of the core elements of foreign policy roles and strategic culture (Desch, 1998: 169; Glenn et al., 2004).

Party politics and policy entrepreneurs

Neo-classical realists argue that state institutions, such as ministries, government agencies, representative institutions, and bureaucracies, play a crucial role in shaping domestic responses to external, systemic pressures (Rose, 1998). These institutions have their own interests, cultures, and modes of operation, which can influence the formulation and implementation of foreign policy. The institutional structure shapes and channels the political process within a state, including electoral politics, interest group dynamics, public opinion, political culture and the distribution of power and influence among various political actors. A state’s institutional structure and party political process is thus an important intervening variable shaping the strategies, priorities, and goals of its foreign policy (Kitchen, 2010; Raunio and Wagner, 2020).

State institutions and established administrative procedures can often reinforce continuity and inhibit significant foreign policy change (Blavoukos and Bourantonis, 2012: 487; Goldmann, 1988: 54–62). We therefore argue that to explain change, it is particularly important to examine specific conjunctural moments of crisis decision-making, when policymakers operate under intense pressure in contexts that are fluid, contingent and malleable (Gustavsson, 1999: 86–87; Wilson, 2000). In such moments of existential crisis, formal decision-making procedures and institutions are often bypassed to expedite rapid and ad hoc decision-making, creating opportunities for individual policy entrepreneurs to shape alternative policy frameworks (Barnett, 1999; Byman and Pollack, 2001; Deverell and Olsson, 2010; Doeser, 2013; Hermann, 1990: 8; Petersson, 2023).

To sum up, the choice of variables in this framework reflects an effort to systematically capture both the stability and dynamism of foreign policy. Systemic pressures provide the overarching context, shaping the strategic incentives and constraints that states face. These pressures are mediated through foreign policy roles and strategic culture, which explain how states institutionalise and interpret their place in the international system, resulting in gradual changes over time. In contrast, policy entrepreneurs and institutional context become critical during crises, where established patterns are disrupted, and opportunities for radical change arise.

Explaining Swedish foreign policy change

Our empirical analysis examines Sweden’s decision to apply for NATO membership in the wake of Russia’s invasion of Ukraine. Following the approach outlined in the introduction to this Special Section (Martill and Sus, 2024), we have utilised a qualitative research design that draws on process tracing (Beach and Pedersen, 2013), but which emphasises comprehensiveness over strict causal inference. This approach enables us to understand how foreign policy change occurs and what factors account for particular outcomes (George and Bennett, 2005). Paying close attention to timing and the sequences of events, we seek to identify regularities and particular ‘tipping points’ in the foreign policy decision-making process (Guzzini, 2017: 252). The empirical analysis of Swedish foreign policy is based on a triangulation of data to increase the validity of the research findings, including political speeches, policy documents, semi-structured interviews, op-eds and media articles, and secondary academic sources on Swedish foreign policy. ¹

The study proceeds as follows: We begin by examining the shifts in Sweden’s external environment, focusing on the growing challenges to Europe’s security order and the changed geopolitical significance of the Baltic Sea region. These exogenous pressures, we argue, are the primary driver of Sweden’s foreign policy transformation occasioned by its application for NATO membership. However, as we shall see, Sweden’s specific response to these pressures has been crucially mediated by unit-level intervening variables.

Geopolitics and systemic change

Historically, Sweden operated as a peripheral small power, somewhat insulated from great power politics until the Cold War era. The East-West conflict reoriented Sweden’s geopolitical landscape (Andrén, 1979; Bengtsson, 2016; Engelbrekt, 2018). Amid the Cold War’s geopolitical shifts, Sweden adapted by bolstering its military capabilities through a strong territorial army and an independent arms industry. This ‘armed neutrality’ and ‘total defence’ strategy aimed to enhance stability in the strategically sensitive Northern flank, while covertly planning military cooperation with NATO to deter potential Soviet aggression (Dalsjö, 2006).

The end of the Cold War dramatically transformed Sweden’s security and foreign policy foundations. As late as 2013, the Swedish Defence Commission stated in its report that a direct military attack against Sweden was not likely in the foreseeable future (Försvarsberedningen, 2013: 33). This perception of a benign regional security environment persisted until the Ukraine crisis of 2014, which is widely recognised in the literature as a ‘game-changer’ for the European security system and a ‘wake-up’ call for the Euro-Atlantic community (Ekengren, 2018; Granholm, 2014). After 2014, defence expenditure rose in all European democracies, and defence and security cooperation increased significantly (Marrone et al., 2015). However, it was the shock of Russia’s invasion of Ukraine in February 2022 – bringing inter-state war back on the European continent – that has been the decisive catalyst for the transformation of European security and defence policy.

The Ukraine war exposed the geopolitical vulnerability of Sweden. In contrast to the Cold War, ‘the line of confrontation between Russia and NATO has shifted to the Baltic Sea region’ (Bringeus, 2016: 2), where a ‘new normal’ of Russian military incursions in the airspace and territorial waters of its Baltic neighbours emerged (Ekengren, 2018; Wieslander, 2015). The Nordic countries are on the frontline of confrontation between the EU and a recidivist Russia, directly exposed to Russia’s growing military assertiveness (Åselius, 2018; Tyushka, 2018).

By 2022, Sweden thus faced a radically transformed security environment, which left it more exposed and vulnerable than virtually any time in the last 200 years. It could no longer ‘hide’ in the relative obscurity of a strategically peripheral Norden but was now on the front line of renewed confrontation with Russia (Kim, 2024). Moreover, successive defence cuts had hollowed out the Swedish armed forces, which meant that when the Ukraine war began, not only did Sweden face a uniquely threatening geopolitical environment, it also lacked the military capabilities to defend its sovereignty and territorial integrity (Brøgger, 2023; Jonsson, 2024).

Foreign policy roles and strategic culture

In terms of the ideational factors shaping Sweden’s decision to join NATO, we focus on two specific aspects: its foreign policy role conceptions and its strategic culture. As regards the former, we identify four key foreign policy role conceptions identified in the official discourse of speeches and statements on Swedish foreign policy: ‘neutral state’, ‘small state realist’, ‘liberal internationalist’ and ‘reliable European partner’. As one would expect given the theoretical expectations of neoclassical realism, Sweden’s role conceptions changed considerably with the end of Cold War bipolarity. A notable transformation was the dropping of ‘neutrality’ and a new role conception of ‘reliable European partner’ emerging (Aggestam and Hyde-Price, 2015). Over time, this was to generate growing role conflict within its role set.

‘Neutral country’

Swedish foreign policy and national identity has been profoundly shaped by its historical legacy of neutrality and non-alignment (Bjereld and Möller, 2015; Malmborg, 2001). Generations of Swedish diplomats and politicians have reiterated the mantra that it has ‘served Sweden well’ (Eliasson, 2023) – a widely held conviction that continued to be intoned even after the Russian invasion of Ukraine. Neutrality (and after 1992, ‘military non-alignment’) has provided the bedrock of Sweden’s foreign policy identity as a small power advocating a liberal internationalist role and ‘doing good’ in the world (Aggestam, 2007). Neutrality, of course, takes many forms. In the case of Sweden, it was a political interpretation (rather than a treaty obligation) that provided policy-makers with a certain autonomy to be pragmatic, flexible and malleable. This included redefining its security policy in terms of ‘military non-alignment’, a more flexible and less politically freighted term than ‘neutrality’. Sweden was to be ‘non-aligned in peacetime, in order to enable Sweden to remain neutral in the case of war in its vicinity’ (Ojanen et al., 2000: 373). Military non-alignment thus shared the same essential traits as neutrality, with a focus on national self-interest, decision-making autonomy, and self-reliance.

‘Small state realism’

Although many Swedes associated neutrality with a sense of moral righteousness (Dahl, 2006), in practice it involved a pragmatic willingness to accommodate itself to the imperatives of the regional balance of power. This coolheaded calculation of its national security and state interests gave rise to a distinctive foreign policy role — ‘small state realism’. In the Cold War, for example, Sweden’s ‘armed neutrality’ and high-profile criticism of US foreign policy was accompanied covert defence planning with NATO and the United States (Dalsjö, 2013; Holmström, 2023). While Sweden was a vocal advocate of a transformation in the global South, in Europe it was a status quo power, seeking to preserve the ‘Nordic balance’ and contribute to détente and peaceful coexistence (Makko, 2012). Sweden’s cold war neutrality was thus combined with a ‘small state realism’ that was deeply engrained in the Swedish security community.

‘Liberal internationalist’

Sweden’s third key foreign policy role conception was that of liberal internationalism. Former Foreign Minister, Olof Palme, was instrumental in shaping this role (Ekengren, 2011), which was pursued primarily through the UN system, giving Sweden the opportunity to pursue a progressive and activist foreign policy built on ideas of ‘common security’ and a commitment to international development, disarmament, and peacekeeping. From the 1970s onwards, this liberal international role conception increasingly took on a moralistic hue, as Sweden began to portray itself as a ‘moral superpower’, committed to ‘saving strangers’ (Ingebritsen, 2002; Wheeler, 2000) and acting as a ‘force for good’ in the world (Aggestam, 2007; Bergman, 2004).

In the Cold War therefore, the parameters of Swedish foreign policy were framed by the tension between the two role conceptions of ‘small state realism’ and ‘liberal internationalism’. Each was based on their own distinct logics: the former, with its focus on sovereignty and survival, was linked to military power, statecraft, and national interests; the latter, with its concern for duties beyond borders, was grounded on a broader conception of security and a normative commitment to international peace and cooperation. Despite the inherent tension between the realist and liberal strands of Swedish neutrality, this never generated acute role conflict that called into question the fundamental orientation of Swedish foreign policy.

‘Reliable European partner’

The seeds of a more profound and ultimately irreconcilable role conflict at the heart of Swedish foreign and security policy were planted by the development of a new role conception – that of ‘reliable European partner’. The demise of cold war bipolarity led to one of the most important decisions in modern Swedish history – joining the European Union. It was this decision above all else that transformed Sweden – economically, financially, politically, and diplomatically. Participation in the European integration process gave Sweden a new stake in the prosperity and stability of the continent and provided the catalyst for a gradual, but irrevocable Europeanisation of Swedish foreign policy (Brommesson, 2015; Rieker, 2004: 385).

To facilitate accession to the EU, Sweden formally dropped ‘neutrality’ while still maintaining the policy of military non-alignment (Gustavsson, 1999; Sundelius, 1994). At the same time, Sweden took part in the UN peacekeeping operation in Bosnia. It also participated enthusiastically and actively in NATO’s 1994 Partnership for Peace programme (PfP), over time developing ever closer links with the alliance and becoming more active in NATO operations than several NATO members (Cottey, 2013; Forsberg and Vaahtoranta, 2001; Möller and Bjereld, 2010). From the early 1990s, therefore, Sweden moved away from being a ‘security consumer’ in Europe to being a ‘security provider’. From being a military ‘hedgehog’ hiding away in its Nordic fastness, it became actively engaged in the management of the European security order. This has gone hand and hand with a strengthening of the instrumental use of the Swedish military for political influence – in line with its tradition of small state realism – through extensive participation in EU and NATO missions (Aggestam and Hyde-Price, 2015; Cottey, 2013; Lee-Ohlsson, 2009).

The logic underlying this new role of ‘reliable European partner’ involved both a deepening sense of European solidarity and a broader understanding of its security interests. The report by the Swedish Parliamentary Defence Committee of 2004 was a milestone in this regard; instead of reiterating semi-isolation and narrow national security interests, it now argued that,

It is hard to imagine that Sweden would be neutral in the event of an armed attack on another EU country. It is equally difficult to imagine that other EU countries would not act in the same way (Report by the Swedish Defence Committee, 2005 [2004]: 5, 23).

This shift towards a more cooperative understanding of Swedish security was underlined in 2009 when, following the ratification of the EU Lisbon Treaty, the Swedish Parliament adopted a Solidarity declaration – a decision which had far-reaching implications for its defence policy (Tolgfors, 2010; Winnerstig, 2014).

Sweden will not remain passive in a catastrophe or if an attack happens another member state or Nordic country. We expect in return that these countries will act in the same way if Sweden is attacked. Sweden should have a capacity to give and receive military support (quoted in, Hugemark, 2012: 1).

This new commitment to political and military solidarity with its Nordic neighbours and European partners sat uneasily with its continuing emphasis on military non-alignment, giving rise to a ‘two-dimensional game of solidarity and sovereignty’ (Christiansson, 2010: 1). The tension between the two distinct logics of ‘military non-alignment’ (with its emphasis on national security and sovereign decision-making) and ‘reliable European partner’ (with the promise of solidarity with others and ‘giving and receiving military aid’) was to generate a deepening role conflict at the core of Swedish foreign and security policy (Bertelman, 2014; Interview, 9 February 2024). As one analyst wrote, ‘Today the complexities of Swedish policy in this field are so many and so intricate that even seasoned Swedish diplomats have problems delivering a logical, coherent presentation of Swedish security policy to foreign and domestic audiences’ (Winnerstig, 2014: 35).

When Europe still seemed to be at peace and the likelihood of Russian military aggression against other states seemed remote, this deepening role conflict was easier to manage. However, once great power competition and geopolitical rivalries broke out into the open in 2014 with Russian aggression against Ukraine, this role conflict became acute, and was only resolved by the application to join NATO in 2022.

Swedish strategic culture

The second aspect of the ideational factors shaping Sweden’s decision to join NATO is its evolving strategic culture. During the Cold War, Sweden’s strategic culture was rooted in its policy of ‘armed neutrality’ and led to a ‘hedgehog’ strategy based on the doctrine of ‘marginal deterrence’ (Åselius, 2005; Ericsson, 1996; Shavell, 1992). With the end of cold war bipolarity, Sweden’s geostrategic environment was transformed (Gyldén, 1994). Sweden no longer faced an existential threat and Swedish defence policy was based on the assumption that armed aggression against the country was unlikely for the foreseeable future (i.e. at least ten years). As late as 2014, Prime Minister Reinfeldt (2014) maintained that the most pressing threats were not military and that Sweden ‘cannot have Armed Forces focusing on territorial invasion at a time when the threats are borderless and complex’.

After the end of the Cold War, therefore, Swedish strategic culture was transformed away from a focus on territorial defence to a new concern with Peace Support Operations and expeditionary missions (Dandeker and Gow, 2000: 60; Wyss, 2011). Swedish strategic culture also evolved considerably as a result of Sweden’s growing participation in a broad range of EU and NATO expeditionary operations, leading to the growing internationalisation of the Swedish armed forces, and strengthened interoperability with EU and NATO partners (Egnell, 2015; Herolf, 2013: 6).

Sweden’s role conception as a ‘reliable European partner’ meant that it increasingly saw itself as an active and committed participant in collective European security and defence, with European ‘solidarity’ emerging as central to its changing strategic culture (Bjurner, 2005). After the Russo-Georgian war of 2008, the Swedish security community became increasingly aware of the threat posed by the growing threat from Putin’s Russia (Interviews, 12-13 February 2024), which led to growing emphasis on solidarity and military cooperation with EU allies and NATO partners. Its Nordic neighbours were particularly important in this respect, and Sweden was instrumental in the creation of NORDEFCO (Nordic Defence Council) in 2009, which aimed at facilitating and promoting Nordic defence cooperation and joint capacity-building (Brøgger, 2023; Dahl, 2014; Forsberg, 2013; Saxi, 2019).

The emergence of a ‘two-dimensional game of solidarity and sovereignty’ (Christiansson, 2010: 1) – formally maintaining ‘military non-alignment’ while placing growing emphasis on solidarity with Nordic and European partners – led to deepening ambiguities in Swedish strategic culture (Lundqvist, 2022). The problem was particularly acute because of Sweden’s military weakness and its defence vulnerabilities. These were underlined by the Head of the Armed Forces, Sverker Göranson, who warned in his New Year 2013 speech that Sweden would only be able to defend itself from military attack for about a week, after which it would need support from neighbours (SvD, 2012). This started a broad-ranging debate about Swedish defence policy, including a growing concern reflected in public opinion (MSB, 2014), which lead to broad cross-party support for strengthening the defence of Sweden’s territory (Holmström, 2014).

A more profound transformation of Swedish strategic culture occurred as a result of the Crimea crisis of 2014. This led to major changes in Swedish policy. Defence expenditure increased for the first time in decades; the Swedish armed forces switched their focus to territorial defence, with the immediate priority being the remilitarisation of the strategic island of Gotland; plans for ‘Total Defence’ were dusted off and revised (Rossbach et al., 2019); and military cooperation with Nordic and European partners was deepened (Kennedy and Schmitt, 2020). Sweden also joined the ‘Enhanced Opportunities Partnership’ with NATO at the 2014 Newport NATO summit, where it signed a ‘Host Nation Support’ (HNS) Memorandum of Understanding (MOU), and other technical agreements that brought Sweden ever closer to the operational decision-making planning of the Alliance. This was complemented by deepening bilateral defence cooperation with the United States and strengthened defence cooperation with Germany (Frisell and Sundberg, 2017).

A landmark decision – and one which was very hard to square with ‘military non-alignment’ – was the deepening bilateral defence cooperation and naval integration with Finland, which developed dynamically after 2014 (Nyberg, 2024). Sweden and Finland had long cooperated on defence planning, and in 2014 they agreed an action plan which led to further steps in defence cooperation and integration (Lundqvist and Widen, 2016). Sweden and Finland also decided to join the UK-led Joint Expeditionary Force (JEF), a nine-nation framework for creating a rapidly deployable force capable of conducting the full spectrum of operations, from humanitarian support to combat (Heier, 2019).

Sweden’s strategic culture has thus been reshaped through a combination of exogenous shocks and weaknesses in national military capabilities that have exposed Sweden’s vulnerability to intensifying geopolitical competition. Swedish defence planners have responded by developing a concept of security based on three layers or concentric circles. The first is national deterrence which seeks to transform Sweden into an indigestible and prickly hedgehog, capable of holding out until outside help arrives (Andrén, 2014; Jonsson, 2024; Neretnieks, 2016). The second is regional deterrence in the Nordic region: at the core of this is Swedish-Finnish defence cooperation, but it includes NORDEFCO and the JEF. The UK-JEF also serves as a link to the third circle, European and transatlantic deterrence. This provides the most important layer of deterrence, linking Europe with the United States through NATO. Even before applying for NATO membership, successive Swedish governments have recognised that it is NATO, not the EU, that is the key institution for collective security in Europe, and that transatlantic security cooperation provides the bedrock and backbone of the European security order (Interviews 12-13 February, 2024).

The problem with this strategic concept was the tension and ambiguity between Sweden as a ‘reliable European partner’ and its continuing attachment to military non-alignment, a tension manifested in growing role conflict and discursive dissonance (Hagström, 2021). For the three layers or concentric circles of deterrence to be effective, they needed to be mutually reinforcing and interlocking (Friis and Tamnes, 2024; Mälksoo, 2024). Swedish defence needed to seamlessly interlink with Nordic-Baltic and transatlantic defence, and for this collective defence planning was critical (Edström and Ångström, 2024). Giving and receiving military aid cannot just happen overnight; it requires detailed logistical planning and preparation (Saxi, 2022). Sweden’s contribution to regional and European deterrence has lacked credibility because it has reserved the right to opt out at the last minute. This lingering attachment to non-alignment thus set limits to the scope of Nordic and European defence cooperation and weakened deterrence. As the Report on the Inquiry on Sweden’s International Defence and Security Cooperation (2016) noted,

‘The most tangible military consequence of Swedish NATO membership would be to dispel the current uncertainty regarding common action in the event of a Baltic Sea crisis, and that the West’s deterrence therefore most probably would increase’ (Bringeus, 2016: 57).

As we have seen, strategic culture tends to persist over time, but is not static, and can change when confronted with an external shock which opens a window of opportunity for policy entrepreneurs to reinterpret or redefine its key assumptions (Heiko et al., 2013: 12–13; Hermann, 1990). Russia’s invasion of Ukraine in February 2022 constituted just such a critical juncture, allowing policy entrepreneurs within the security community to reformulate the core tenets of Swedish strategic culture, thereby resolving the problem of discursive dissonance and policy ambiguity.

Party politics and policy entrepreneurs

In terms of Swedish domestic political structures, we focus on two key elements: Sweden’s state institutions and the political process, and the role of policy entrepreneurs in crisis decision-making. As a small state, Sweden long sought to carve out a distinctive role for itself as a neutral/non-aligned country, pragmatically navigating the shifting tides of international politics while preserving its sovereignty and independence. But for this policy to be credible and effective, it was essential that its foreign policy enjoyed broad cross-party support and was embedded in Swedish political culture. For decades therefore, neutrality/military non-alignment served as a closed belief system which should not be questioned as that would undermine its credibility (Goldmann, 1988).

For much of Sweden’s history, neutrality garnered broad public support, particularly in the twentieth century when Swedish politics was characterised by a consensus-seeking political culture and shaped primarily by the Social Democratic party (SAP), which was the hegemonic force in Swedish politics for most of the twentieth century (Interview 9 February, 2024). All of Sweden’s key foreign policy role conceptions were largely framed by the hegemonic SAP and broadly accepted by the other parties. Over the last two decades, however, the bipartisan consensus on security policy started to break down, primarily because of the gradual but far-reaching transformation of Swedish identity caused by membership of the EU (Hagström, 2021; Lundqvist, 2022). The resulting new role conception of ‘reliable European partner’ prised open discursive space for voices more critical of non-alignment and more positive towards NATO membership. In 1999, the Liberal party became the first to come out in favour of NATO membership. The Moderate party congress shifted its position in 2003 and proposed that Sweden should join NATO, but only in tandem with Finland. Interestingly, they saw no rush to do this and continued to support the broad cross-party consensus on military non-alignment, arguing that NATO membership was an aspiration not an immediate goal.

A pivotal moment for Swedish foreign and security policy was the Lisbon Treaty of 2009, which led the Swedish Parliament to adopt its own solidarity declaration and to formulate its defence policy in terms of being able to give and receive military support in the event of a disaster or attack (Statement of Government Policy, 2010). This new collective approach to defence – which was very little discussed in Sweden – had far-reaching implications for Swedish security policy and introduced a dissonant strand within its strategic culture. The solidarity declaration set new discursive parameters for the political debate on Swedish security policy and provided additional opportunities for contesting the dominant role conception of military non-alignment. Henceforth the discursive dissonance and role conflict at the heart of Swedish security policy became much more apparent, and as the cross-party consensus disintegrated, the issue of military non-alignment became an issue of party-political contestation.

By the time of the Swedish election in September 2014 – won by the Social Democrats led by Stefan Löfven, in coalition with the Green Party – defence became an issue of party-political debate, and the issue of NATO membership more ideologically charged along the left-right spectrum. After the shock of Russia’s annexation of Crimea, both the Christian democratic party (KD) and the Centre Party (CP) in 2015 came out in favour of NATO membership. With the cementing of a bloc of centre-right parties that advocated joining the transatlantic alliance, foreign policy role conflict increasingly took on a party-political dimension, fracturing the carefully nurtured consensus on defence policy and strategic culture (Anthony and Weintraub, 2018: 11; Hagström, 2021).

Many in the Social Democratic party had a strong attachment to the legacy of Palme and neutrality. As one long-standing Swedish diplomat reflected, ‘the Swedish Social Democratic party was the hegemon in Swedish foreign policy’, particularly when it came to non-alignment, which is why they consistently sought to keep the issue of the ‘NATO option’ off the table in (Interview 9 February, 2024). However, it is important to note that the party itself has always contained a broad range of different groupings and perspectives. The debates and contestation between ‘military non-alignment’ and ‘reliable European partner’, or between ‘small state realism’ and ‘liberal internationalism’, were played out within the SAP as well as across the broader political and security community. Nonetheless, when it came to the issue of military non-alignment and NATO membership, the SAP was still marked by a strong normative commitment to non-alignment.

Differences within the Löfven government on issues such as the correct balance between the UN and EU/NATO missions, or between the roles of military non-alignment and reliable European partner, were also reflected in differing bureaucratic interests between governmental institutions, particularly between the Ministry of Foreign Affairs (MFA) led by Margot Wallström, and the Ministry of Defence (MoD), headed by Peter Hultqvist. The MFA is one of the largest governmental ministries and has been deeply shaped by the legacy of Palme, ‘neutrality’, and ‘liberal internationalism’. Foreign Minister Wallström saw herself as heir to these traditions, pursuing a feminist foreign policy with a radical liberal internationalist agenda and an emphasis on the UN and disarmament (Aggestam and Bergman-Rosamond, 2016). The MoD, on the other hand, has benefitted institutionally and resource-wise from deepening defence cooperation with EU and NATO partners, and contains many small state realists. For the MoD, participation in international crisis management and contributions to EU and NATO missions allowed Sweden to ‘punch above its weight’, enhancing its international voice and influence (Aggestam and Hyde-Price, 2015). The MOD was also more receptive to dissenting voices in the security community and the Armed Forces, who viewed NATO membership as the only way to resolve the deepening incoherence of Swedish defence policy. Peter Hultqvist himself was the archetype of a pragmatic social democratic politician, pushing for ever deeper defence cooperation with NATO, while emphasising his own continued political commitment to military non-alignment. Thus, for example, in September 2014 he called for the Swedish government to sign a Memorandum on Host Nation Support with NATO facilitating Sweden’s ability to receive military aid from NATO forces (Atlantic Council, 2016).

The most serious clash within the Löfven government – which exposed the divisions in strategic culture and deepening role conflict – took place in 2017 around the issue of global nuclear disarmament. Foreign Minister, Wallström, argued that Sweden should sign the UN Treaty on the Prohibition of Nuclear Weapons (TPNW), which had been opposed by successive US administrations since Obama. After receiving a confidential letter from US Secretary of Defence, James Mattis, which warned that Swedish accession to the UN Treaty would negatively affect Sweden’s collaboration with the USA and NATO, Hultqvist made clear that supporting the TPNW would weaken Swedish security (SvD, 2017).

This tug of war between Wallström and Hultqvist was resolved by the appointment of a former diplomat, Lars-Erik Lundin, who was tasked with evaluating the consequences of Sweden signing the TPNW. His conclusion was that the Treaty would lead to ‘a stagnation of current cooperation with NATO and bilaterally with NATO members’ and ‘would without any doubt prevent a possible future Swedish membership of NATO’ (Lundin, 2019: 45–47) – which effectively ended the inter-ministerial conflict on the matter.

The resort to expert advice in the form of commission reports chaired by seasoned and respected diplomats is a well-established tool in Swedish politics for dealing with thorny and divisive political issues. Other significant examples include the commission reports when Sweden joined the EU (SOU, 1994: 8) and the 2016 report ‘Security in a New Age’ (Swedish Government, 2016: 57). The use of expert advice at times of political contestation illustrates the consensual style of Swedish political culture, particularly when dealing with the ‘high politics’ of foreign policy and national security. This consensual political culture is underpinned by a strong faith in experts and technocrats, whose advice is used as a tool to bypass or transcend intractable political differences.

Within the Swedish Parliament, the main centre-right parties had all embraced the option of NATO membership by the start of 2022. This was vociferously opposed by the Left Party (V) and the Greens (MP), while the Swedish Democrats (SD) continued to look back with nostalgia to the era of neutrality. The SAP continued to defend military non-alignment, but their approach was much more pragmatic and flexible – particularly given their commitment to coordinate any NATO application with Finland. The Social Democrats were also aware that since 2014, Swedish public opinion had steadily been shifting in favour of NATO membership (Ydén et al., 2019).

On the eve of the Russian invasion of Ukraine, therefore, it was evident that there was growing openness towards the ‘NATO option’, which was advocated by sections of the security community, supported by the centre-rights parties, and viewed more sympathetically by public opinion. The main blockage was the Social Democratic party who were unable to overcome the deeply cherished role of non-alignment that was associated with the liberal internationalist role of a progressive and activist foreign policy. As we shall see, the logjam was only broken by two external triggers – the first from Russia, the second from Finland.

Swedish policy entrepreneurs and crisis decision-making

This section analyses the crisis decision-making process from Russia’s invasion of Ukraine on 24 February 2022 to the Swedish-Finnish application for NATO membership on 16 May 2022. During this critical period, individual politicians and policy entrepreneurs played a decisive role, challenging long-standing policy paradigms and legitimising policy change.

On the eve of the Russian invasion of Ukraine, Sweden had a minority social democratic government led by the country’s first female Prime Minister, Magdalena Andersson. She had a background in economics and finance but was relatively inexperienced in foreign and security policy. She was, however, popular among the public and had a very strong position in the party, making her a pivotal figure in Swedish politics at this time. Foreign and defence policy were overseen by Ann Linde and Peter Hultqvist respectively. Both were experienced politicians with a commitment to traditional Social Democratic values and traditions, and both shared a commitment to military non-alignment. However, while Foreign Minister Linde was more associated with the liberal internationalist role conception, Defence Minister Hultqvist was associated more with ‘small state realism’ and ‘reliable European partner’. A veteran in security and defence policy, Hultqvist had a significant influence of Sweden’s defence stance, shaping what became to be known as the ‘Hultqvist doctrine’ (Lundqvist, 2022; Wieslander, 2022). This doctrine emphasised increased defence expenditure and enhanced military cooperation with the EU, NATO, the USA, and the Nordic nations, while staunchly rejecting binding security commitments that could compromise military non-alignment.

The ’Hultqvist doctrine’ remained the keystone of Sweden’s security and defence policy right up to and beyond the Russian invasion of Ukraine. Hultqvist held on to his promise from the party congress in 2021 that ‘[t]here will be no application of any membership as long as we have a Social Democratic government’ (DN, 2022). Similarly, Foreign Minister Linde maintained that ’our military non-alignment has served us well and contributes to stability and security in Northern Europe’ (Statement of Government Policy, 2022).

With the Russian invasion of Ukraine, the Swedish government continued with this two-track approach – on the one hand, reaffirming military non-alignment, on the other, intensifying and expanding defence cooperation with Nordic, EU, and NATO partners. However, indications of a more significant change soon emerged when Finland began to explore the option of NATO membership (Pesu and Iso-Markku, 2024). Concurrently, the political terrain in public opinion was shifting. Already in February 2022, opinion polls indicated that 51% of Swedes now favoured NATO membership (Demoskop, 2022). This huge shift in public opinion was accompanied by statements from the right-wing nationalist party, the Sweden Democrats (SD), that they might now consider NATO membership (Reuters, 2022). This opened the prospect of majority parliamentary support in favour of NATO membership.

As the tide of public opinion shifted, and the SD began re-evaluating their approach to Swedish security, Defence Minister Hultqvist sought to hold the line, insisting that ‘To change the defence doctrine. . . is a huge decision. . . You don’t do it overnight and you cannot do it because of opinion polls’ (Reuters, 2022). The Swedish government also hoped that existing security commitments would make NATO membership unnecessary. Ahead of the EU summit in France, Sweden and Finland submitted a joint letter to EU members reminding them of the mutual defence clause in the 2009 Lisbon Treaty (SR, 2022c). With discussions on NATO membership well underway in the Finnish parliament, Prime Minister Andersson held security discussions with other party leaders, four of which (M, KD, L and C) argued that the current situation made a NATO application both timely and essential. Later, on 16 March, Foreign Minister Linde and Defence Secretary Hultqvist began informal talks on the security situation with all political parties, although Magdalena Andersson continued to maintain that ‘A (Swedish) NATO application now would destabilize this part of Europe even further’ (SVT, 2022a).

However, within a few weeks Prime Minister Anderson adopted a more flexible and pragmatic position, stating that ‘I don’t think we should exclude anything in this situation’ (SVT, 2022b). On 2 April, Finnish Prime Minister Sanna Marin told a conference of her Social Democratic colleagues that it was time for Finland to reconsider its security policy and that any decision to apply for NATO membership would have to made ‘thoroughly and quickly’ (Yle News, 2022). This signal from Finland led to a further strengthening of support for NATO membership in Swedish public opinion (Bjereld and Oscarsson, 2023: 6). Moreover, on 9 April, Swedish Democrat party leader, Jimmie Åkesson, stated that if Finland decided to join NATO, Sweden should do so too (SvD, 2022). This shift by the second biggest opposition party created a majority in the Swedish Parliament for NATO membership.

A decisive moment in the Swedish decision-making process to jettison two hundred years of neutrality and military non-alignment was made on 11 April 2022. In a meeting with a handful of trusted advisors in a windowless secure room in the Defence Ministry, Defence Minister Hultqvist finally decided that Sweden should join Finland in applying for NATO membership. Having examined the various options facing Sweden, he concluded that it was ‘no longer realistic’ to continue with military non-alignment. To do so once Finland had decided to join NATO, would leave Sweden in the ‘B-league’ of Nordic defence cooperation and mean that defence expenditure would have to rise to 3.5 or 4% of GDP, not just 2% as planned. He also pointed to the geostrategic importance of the island of Gotland, and the existential challenge to Sweden if it remained outside NATO in a crisis (DN, 2022). With this decision by the progenitor of the ‘Hultqvist doctrine’, the days of Swedish military non-alignment were clearly numbered.

For Hultqvist, this was not an easy decision to reach. As a long-standing social democrat, military non-alignment was for him a lodestar of Swedish security policy. But he was also an archetypal social democrat ‘small state realist’, who had long warned of the dangers posed to the European security order by Putin’s Russia. As he was subsequently to say, ‘it is difficult to have a new position after all these years. For my part, it is about a whole political life where we’ve had non-alignment as the foundational bolt. And which I think has been good and right’ (DN, 2022). Although he did not publicly declare his change of heart at this time, he did indicate that all options were now on the table. It was only after the historic decision by the Social Democratic party leadership on Sunday 15 May 2022 to apply for NATO membership that Hultqvist publicly announced his renunciation of the ‘Hultqvist doctrine’ (Socialdemokraterna, 2022).

It was perhaps fortuitous that it was a social democratic government that had to grapple with the implications for Swedish security and defence policy of the Ukraine war and the Finnish decision to join NATO. If the centre-right parties had been in power, it may well have been more difficult for political entrepreneurs within the SAP to overcome the deep-seated ideological attachment of party stalwarts to the policy of military non-alignment. This would have politicised any application for NATO membership and weakened the consensual nature of Swedish security policy. Although the social democrats no longer held the hegemonic position in Swedish politics that they had enjoyed for much of the twentieth century, they were still the largest and most popular political party – emerging as the single largest party in every general election since 2017 (Therborn, 2018). Being in government when Sweden faced its most severe security crisis for decades forced them to confront the changed security environment and gave opportunities for policy entrepreneurs to articulate an alternative policy course. The social democrats were also aware that Swedish public opinion was changing in favour of NATO membership, and with a new election due in September 2022, they did not want to find themselves having to defend the increasingly discredited policy of military non-alignment (Interviews, 12-13 February 2024).

Throughout April and early May, therefore, the crucial political battleground over which the decision on NATO was fought and ultimately decided was the Social Democratic party. The party itself was deeply divided, with many party activists viewing NATO with deep suspicion. In party meetings up and down the country the issue was fervently discussed and debated. There was broad recognition of the threat posed by Russia’s invasion of Ukraine, and awareness that Sweden’s most important ally and defence partner Finland – with which it shared deep historical, cultural, and political ties – was set on joining the alliance (Pesu and Iso-Markku, 2024). But there was also a passionate desire for Sweden to continue to have a strong and independent voice on issues of peace, disarmament and democracy, and a concern that NATO membership would constrain this. Opponents of joining NATO, like the former Swedish ambassador to Russia, Sven Hirdman (2022), argued that Sweden would lose its security policy identity, find itself tied to the US and would become a front-line state in the military confrontation with Russia.

In the context of a deeply divided party and the entrenched opposition of the Social Democratic old guard, the contribution of respected figures like former Foreign Minister, Margot Wallström – who once dismissed calls for Sweden to join NATO as ‘absurd’ – and retired senior diplomats, like Jan Eliason (SR, 2022a), was particularly important in reforging a new consensus within the SAP. They both came out in favour of joining NATO together with Finland. As Wallström argued (FT, 2022), ‘It’s not ideal to have a decision like this when fear is the emotion that people have’, but she continued, ‘maybe fear is what forces us to make these important decisions’. Her primary concern, she argued, was ‘to avoid the country and the party becoming split forever’ and she indicated that although Sweden should not be ‘suddenly silenced on what we hold dear’, the political mood of the country, and the weight of informed opinion means that ‘it only takes us in one direction’ – indicating that she believed that joining the alliance was the only possible conclusion. She also noted that ‘Everybody trusts Magdalena’, which underlines the popularity of Prime Minister Andersson, and the strong hold that she had over the party. This was important once the party leadership had taken the decision on 15 May 2022 to apply for NATO membership, because it meant that the bulk of the party remained united behind the new consensus policy – despite pockets of opposition.

The Social Democrat’s watershed decision to support an application for NATO membership came shortly after the unequivocal decision by Finland on 12 May to apply for NATO membership. It also followed the publication on 13 May of a historic Foreign Ministry memorandum. This memorandum –A deteriorated security policy situation: consequences for Sweden – presented the findings of a cross-party working group chaired by Foreign Minister Ann Linde (Swedish Ministry for Foreign Affairs, 2022). The conclusion of the memorandum – which was supported by six out of eight parties in Parliament (with the Left Party and the Greens dissenting) – was that only the collective defence guarantees of NATO could provide the security Sweden needed. With this memorandum, the die was cast. On 16 May, the Swedish government formally decided to apply for NATO membership, and on 17-18 May 2022, the application was signed by Foreign Minister Linde and handed over NATO Secretary-General Stoltenberg by Sweden’s ambassador to NATO, Axel Wernhoff, at the same time as Finland also applied (Pesu and Iso-Markku, 2024: 569).

Two hundred years of Swedish neutrality and non-alignment thus ended. Ironically, it was the Social Democrats, who – having consistently striven to keep the issue of NATO membership off the political agenda for decades – in the end were forced to confront the contradictions and paradoxes of the ‘Hultqvist doctrine’, and after a short but intense inner-party debate, lead Sweden into the transatlantic alliance. In doing so, they preserved the unity of their party and reinforced the long tradition of consensual security and defence policy making in Sweden. This new consensus was underlined at a joint press conference on 16 May 2022 when Prime Minister Andersson and the leader of the main Conservative opposition party, Ulf Kristersson, together endorsed the decision to join NATO. ‘The best for Sweden’s security and the security of the Swedish people is for Sweden to join NATO, and to do it with Finland’, Magdalena Andersson stated, adding that ‘We are leaving one era and beginning another’ (SR, 2022b). For his part, Ulf Kristersson noted that ‘There are many major issues where we think differently, but we are going to take a joint responsibility for the process of taking Sweden into NATO’, adding that ‘NATO is above party politics’ (SR, 2022b). This new national consensus has endured despite the change of government in October 2022, and was again publicly reaffirmed on 11 March 2024 when Prime Minister Kristersson and opposition party leader Andersson held a joint press conference welcoming Sweden’s formal accession to the NATO alliance.

Conclusion

Sweden’s response to the ‘winds of change’ that blew through Europe after Russia’s invasion of Ukraine and the return of interstate war to the continent was to join its close ally Finland in applying for NATO membership. However, as we have seen, this decision did not follow automatically from the watershed events of February 2022, but came later in May 2022 after an intense period of crisis decision-making in which policy entrepreneurs in the Social Democratic party, the Riksdag and the wider defence community were able to utilise alternative discursive strands in strategic culture and foreign policy role conceptions to successfully mobilise key groups in favour of applying for NATO membership.

Major changes in the grand strategy underpinning Swedish foreign policy have always come in the wake of profound structural changes in European order – such as the end of cold war bipolarity and Russia’s invasion of Ukraine. However, they never follow automatically or mechanically from systemic changes. Rather, they are the outcome of more complex political processes and nuanced ideational changes at the domestic level. We argue that it was changes in Swedish foreign policy made in the early 1990s that over time created the facilitating conditions for the decision to apply for NATO membership. Joining the EU and assuming responsibility for the active management of European peace and security led to an incremental transformation of Swedish national identity and strategic culture. This led to a new foreign policy role conception – that of ‘reliable European partner’ – and new cooperative strands to Swedish strategic culture, particularly after the 2009 Solidarity Declaration and the framing of a defence policy based on ‘giving and receiving military assistance’.

Russian recidivism and Putin’s war of territorial aggrandisement against Ukraine led to a seismic shift in European order, creating a new – more vulnerable – geopolitical context for Sweden. The challenge confronting Sweden was that while Putin had invested heavily in the modernisation and transformation of the Russian armed forces (Renz, 2018), Sweden – like most European democracies – had steadily hollowed out their military capabilities for territorial defence. ‘Armed neutrality’ was therefore no longer an option. Initially, Sweden’s social democratic government continued with the twin-track approach of reiterating military non-alignment while deepening defence cooperation with a range of Nordic, European and transatlantic partners. However, following Finland’s decision to join NATO, this was no longer credible, and policy entrepreneurs were able to mobilise a broad political coalition in favour of joining NATO.

The decision to apply for NATO membership was thus Sweden’s ‘crossing of the Rubicon’. This decision had, however, been preceded by a long period of incremental change in which Sweden’s role conceptions and strategic culture had been gradually reshaped and reframed. However, this was not in and of itself sufficient to cause major foreign policy change. Rather, the catalyst was the external shock of Russia’s invasion of Ukraine and Finland’s decision to join NATO. This opened a ‘window of opportunity’ which policy entrepreneurs were able to use to argue successfully for a NATO application.

This empirical finding has some potentially significant implications for the comparative study of foreign policy change. It suggests that major foreign policy change rarely involves a radical ‘180 degree’ reorientation in policy. Rather, it is often the outcome of a more gradual process of ad hoc and incremental change that culminates in a ‘tipping point’ when established foreign policy shibboleths are overturned. The relevant image here is a geological one of pressures building because of shifting tectonic plates below the surface, leading to a more abrupt seismic event. This underlines the importance of additional theoretical development and empirical research to deepen our scholarly understanding of the interaction of systemic and unit level factors, and the mechanisms of foreign policy change.