Introduction

As the list of NATO members and its associated partners continues to grow, it is obvious that the alliance has long ceased to be an exclusive club of like-minded allies, as it was at the moment of its inception in 1949. Back then, there were only 12 founding countries. With new members coming in during the Cold War and after, NATO went from being a military alliance in a strict sense to becoming a full-blown international security organization with 30 member states and the Nordic neutrals (Sweden and Finland) have gotten closer and closer to full-membership status. The tension between NATO as a close-knit defensive alliance and NATO as an open and growing security community, which had been present for some time, gained momentum with the first waves of enlargement following the end of the Cold War, as former members of the Warsaw Pact expressed interest in joining (Goldgeier 1999b, 21). NATO’s core tasks also oscillated between collective defense, which entails presenting a common front against an external threat, and collective security, which is focused on global security management (Rupp 2000, 157–158). Through the process of enlargement, many allies made their preferences clear and pushed for a cooperative security mindset, wanting to socialize more states into NATO as an institutionalized security community of democratic states echoing values and norms espoused by the European Union (EU) and the Organization for Security and Cooperation in Europe. According to Alexandra Gheciu, cooperative security refers to a ‘model of interstate relations in which disputes are expected to be resolved peacefully within the limits of agreed upon norms and established procedures’ and ‘threats to the community’s security are best handled by confidence building, dialogue, cooperative measures and by the inclusion of neighboring states into the community as members or partners’ (2005a, b, 976; see also Adler 2008, 207).

Central and Eastern European (CEE) countries that were candidates for NATO membership were test cases in NATO’s reinvention project. CEE states did not resist the process of socialization that was deemed necessary for accession. Although the process had its limits, socialization was transformative for post-Communist Europe as it gravitated toward liberal democracy (Gheciu 2005a; Epstein 2008). CEE states gained a lot in the process, such as the professionalization and modernization of their armed forces, as well as defense sector reform. But was NATO’s post-Cold War emphasis on collective security compatible with its newer members’ aspirations for collective defense? Today, states that are on Russia’s border (or very close to it) have abandoned the pretense that cooperative security is NATO’s driving logic, which has led to increasing dissonance among NATO’s member states and partners about the alliance’s true purpose and identity.

In this article, we demonstrate that NATO’s socialization efforts did not lead to a transformation of security identities, revisiting some of the constructivist scholarship on NATO. We suggest that the constructivist logic of cooperative security can only flourish under the most favorable security conditions. Indeed, only when threats to transatlantic security are low is NATO’s socialization potential high, which means the constructivist argument could cross the bar easily in the immediate post-Cold War environment. When states perceive that the threat is increasing, however, more traditional (and realist) conceptions of national identity displace the cooperative security model. Although we acknowledge that a great deal of institutional learning happened through the process of NATO accession and partnership building during the post-Cold War era, we argue that the socialization process stopped short of transforming new members’ identities and security mindsets. We agree with historian Timothy A. Sayle’s characterization of the alliance in the 1990s as undergoing a ‘rhetorical transformation’ rather than fundamental change (Sayle 2019, 229).

The contribution of this article, then, is to analyze the different versions of NATO that were proposed in the post-Cold War era. These different versions evolved alongside debates over enlargement at the time. This article first examines NATO’s rebranding efforts, launched with the end of the Cold War, showing why the cooperative security mindset was so appealing at that time. Collective defense, along with NATO’s shrinking deterrence apparatus, went out of style but was not forgotten, as becomes clear in the article’s second section on the Baltic states (Estonia, Latvia, and Lithuania) and Poland. Before concluding, a comparison with NATO’s Nordic partners is introduced to discuss cooperative security in a larger context.

NATO’s rebranding efforts: the alluring promise of cooperative security

In the year 2000, Richard Rupp, who was commenting on NATO’s enlargement, wrote: ‘Aspiring NATO members are seeking membership in the Cold War NATO. But that NATO no longer exists’ (172). In the post-Cold War environment, NATO identified no overarching threat to transatlantic security and tried to communicate as much in its 1991 Strategic Concept. As NATO was adapting to this new security environment, observers of all ideological stripes made predictions about the Alliance’s viability and about how it would have to transform to support regional security management in Europe. After the dissolution of NATO failed to materialize, and as Klein has pointed out, NATO’s ‘political and cultural identity’ became more salient (Klein 1990). Although NATO leaders fretted about Russian resurgence or the possibility of instability in Eastern Europe, these discussions were the purview of elites. Domestic publics needed to be convinced of NATO’s necessity in a post-Cold War world. In the early 1990s, it was not yet clear to what extent NATO would experience a military drawdown, whether or not the USA would remain present on the European continent, or what role nuclear weapons would continue to play, if any, in support of transatlantic security. What was clear, however, was that NATO had more to gain from building up its political role than increasing its military role. As Klein (1990, 320) noted, ‘Western strategists find a greater reserve of support through emphasizing these cultural dimensions of Western policy than through emphasizing the latest round of measures to ensure security against threats from the East.’ Indeed, NATO as an embodiment of Western values was more appealing to domestic publics wanting to cash in on the peace dividend than was fear mongering or strategic hedging in the highly unpredictable post-Cold War environment. To be sure, NATO had always been a political-military alliance. This aspect of NATO’s organizational structure was marketed and made intelligible for public consumption in NATO’s first summit following the fall of the Berlin Wall. In London in July 1990, the NATO heads of state declared: ‘We reaffirm that security and stability do not lie solely in the military dimension, and we intend to enhance the political component of our Alliance as provided for by Article 2 of our Treaty’ (NATO 1990). According to Mary E. Sarotte (2010, 123), the 1990 NATO summit was meant to publicize cosmetic reform efforts: ‘The goal was to make NATO seem less threatening outwardly but to maintain its essential characteristics. The evidence shows that Bonn and Washington made key decisions about reform bilaterally, then vetted them with a few other national leaders, and finally channeled them through the alliance’s bureaucracy for rubber-stamping.’ The idea to emphasize cooperation and partnership, instead of traditional alliance rhetoric, would also, as George Bush and Brent Scowcroft (1998, 293) wrote, ‘help Moscow save face.’ But these plans about NATO’s future were also interpreted by some scholars as a ‘cooperative façade’ (Shifrinson 2016, 43). Although Mikhail Gorbachev wanted a new European security architecture that would include the East, NATO allies would entertain this possibility only if pursued through the existing alliance framework. The USA, especially, wanted a downsized role but was skeptical of relying on a strictly European security construct to manage the unpredictability of the post-Cold War era.

At the Brussels summit in 1989, the alliance had expressed optimism regarding widespread change in Eastern Europe, but at that time the Berlin Wall had not yet fallen and much of the Brussels Summit declaration focused on improving East–West relations, arms control, and confidence-building measures, while re-emphasizing NATO’s status quo (NATO 1989). By initiating a rebranding effort in 1990, NATO’s new vocabulary promoted engagement with Moscow and an invitation to the newly democratic CEE states to participate in the transformation of European security. This discursive shift represented a public diplomacy tour de force, but in practice, the fundamentals of NATO remained intact. As Sayle (2019, 218) put it: ‘An American supreme commander remained atop an integrated command structure that planned for war in Europe. In fact, NATO’s military integration only deepened after [the] collapse of the Warsaw Pact.’ The USA remained wary of Russian military capabilities, and the UK feared that US withdrawal from the European continent and the changes in Eastern Europe represented a potential threat to the relatively peaceful transition out of the Cold War. Although the end of the Cold War itself was significant, it did not alter NATO’s day-to-day work as much as its representatives suggested to international audiences. In the allied capitals of the 16 member states that were trying to make sense of the fall of the Berlin Wall, politicians were quick to present NATO as an alliance transformed, based on political values and not geared toward any particular adversary. This framing had enduring appeal and provided a solid enough basis on which to grow in size and in scope.

Indeed, the rebranding of NATO as a collective security organization greatly facilitated enlargement. Although there were strong arguments against NATO’s eastward expansion, the coalition in favor of it carried the day.Footnote 1 That coalition included CEE elites, members of the US administration who wanted to check Russian resurgence, and domestic publics in the USA and Europe who bought into the new narrative about NATO or the idea of spreading democracy as the key to European peace and stability (Deudney and Ikenberry 2009). The Eastern European diaspora in the USA and in Western Europe also represented an important voice supporting NATO enlargement.

The Czech Republic, Hungary, and Poland were the first to embark on accession talks. Schimmelfennig (1998) argued that these three countries became the first new members because they were closest to meeting the established accession benchmarks, and like Adler (2008), he argued that the enlargement process would lead to CEE countries internalizing NATO’s values and norms through a process of socialization and learning. He suggested that the primary motive for NATO to undertake enlargement was to strengthen its community of values and norms and to build peace based on those values, which in turn would strengthen liberal democracy. Indeed, as liberal and constructivist ideas linked democracy to increasing the prospects for peace, this immediately captured the attention of policymakers who saw democratization as the path to achieve world peace. In the enlargement debate of the 1990s, President Bill Clinton justified the US pro-enlargement stance in these terms: ‘President Bush helped to reunify Germany. Now for the very first time since nation-states first appeared in Europe, we have an opportunity to build a peaceful, undivided and democratic continent’ (quoted in Mitchell 1996).

Constructivist scholarship has characterized this important post-Cold War development as a process by which aspiring and new allies were socialized by NATO, which acted as a community of practice (Adler 2008, 195). Adler (2008, 196) defines communities of practice as ‘like-minded groups of practitioners who are informally as well as contextually bound by a shared interest in learning and applying a common practice,’ with the ability to create spaces ‘where learning takes place and meanings and identities are negotiated and transformed.’ This process of socialization did represent an important common learning exercise, introducing new members to NATO’s rules. Although one can argue that NATO’s potential new members acted instrumentally—initially pursuing NATO membership because they still perceived Russia as a potential threat—their adherence to an organization that relied on cooperative security practices, rather than to a purely defensive alliance, could very well have contributed to a change of attitude regarding their security predicament over time. From the perspective of Central and Eastern Europe, however, the Russian threat did not disappear with the dissolution of the Soviet Union, even though this was an optimistic period for European security.

It is useful to survey the realist arguments here, as realists predicted that enlargement would be a mistake, unnecessarily antagonizing Russia and recreating a regional security dilemma that had (at least temporarily) been solved with the West’s triumph over the East. For realists, the West had few incentives to enlarge NATO. It could capitalize on Russia’s moment of weakness, but expanding its influence eastward would be imprudent and costly. The CEE states, for their part, had clear incentives to bandwagon with NATO for fear that Russia would once again pose a threat to them. Realists made two separate and contradictory arguments regarding NATO enlargement after the Cold War. The first traditional realist view was that NATO had outlived its purpose and would eventually die away (Waltz 1993; Wohlforth 1994/95). Arguments about NATO’s demise remained academic and hypothetical, however, as no member state saw any political incentive to dismantle NATO or formally expressed a desire to do so, despite the costs of maintaining troops in Europe. Further, addressing the costs proved relatively easy in the short term. NATO assets in Europe were reduced and aspiring members boosted their defense spending. What we saw, in fact, was a series of events surrounding NATO’s endurance, which fits neatly with neoclassical realist theory. Although the alliance had structural incentives to cease its activities, the domestic politics of NATO members states ultimately prevented any action from being taken. The second realist argument was that NATO endured because of the persistence of threats in its immediate neighborhood: the Balkans and, as described by Duffield (1994/95, 766), the ‘residual threat posed by Russian military power.’ As conflict in the Balkans erupted in the 1990s, member states (and aspiring members) viewed NATO membership as a comfortable club to be in. The scholarly and policy debates on NATO’s enlargement grew intense in the late 1990s and the early 2000s, but then fizzled out (Bell 1994; Goldgeier 1999a; Reiter 2001; Asmus 2004). After the Baltics were admitted, additional states joined largely unnoticed.

In the meantime, cooperative security took hold institutionally, within NATO, and even gained the status of official policy. As one of NATO’s new post-Cold War pillars, cooperative security took the following forms:

  1. 1.

    Political dialogue to increase confidence through greater information sharing

  2. 2.

    Practical cooperation to establish routine means of political and military engagement

  3. 3.

    Greater transparency in defense planning and democratic control of the armed forces

  4. 4.

    Closer ties with other international security organizations to broaden cooperative security’s reach (Adler 2008, 206–208)

The policy of cooperative security reflected the accession criteria for new members and was an aspirational guideline for NATO’s way of doing business. Coming back to the constructivist arguments, as new states adopted these practices, they would be able to shed their Cold War security mindset, just like the organization as a whole had done. NATO was heavily involved in transferring liberal democratic norms in the field of security to CEE states. These included accountability and transparency in the formulation of defense policies and budgets, the division of powers within the state in the area of security, government oversight of the military through civilian defense ministries, and accountability for the armed forces. In addition, NATO sought to project into CEE countries Western-defined liberal norms and rules of international behavior, in particular those involving peaceful settlement of disputes, multilateralism, and democracy and human rights promotion in the international arena (Gheciu 2005b, 974). According to the cooperative security mindset, then, NATO enlargement was not meant to contain Russia, but to transform NATO’s relationship with it. If we follow the corresponding constructivist logic, socialization is defined as the process by which states are introduced to the norms and rules of the (security) community. This process, then, involves the socializer—NATO—attempting to change the definitions of identity and interests held by the socializees. If a security community is the physical manifestation of an alliance that has transformed its raison d’être from collective defense to collective security, the norm of cooperative security is the dominant security mindset and the frame through which states assess their security choices. The adoption of a cooperative security mindset by its new members should have led to increased willingness to engage with Russia, to deal with any irritants via institutional channels, and to advocate for the eventual inclusion of Russia as a full-fledged partner or ally after sustained dialogue and the establishment of confidence-building measures. According to the cooperative security norm, peaceful change is made possible because states learn appropriate ways to engage with each other through standard-defining institutions and through practices designed to avoid the instability that is generated through unbridled security competition. Because security communities, which promote the logic of cooperative security, are meant to withstand disagreements and embody the ‘non-violent settlement of disputes,’ irreconcilable interpretations of what constitutes the alliance’s common identity are damaging (Pouliot 2006, 124). Cooperative security should have translated into anything but the persistence of longstanding fault lines within NATO over its security priorities.

The Baltic states and Poland: from model behavior to moral hazard?

Whereas Poland was among the first group of states to be offered NATO membership after the end of the Cold War, it took a few more years for the invitation to be extended to the Baltic states. The constructivist argument that stresses the socialization powers of NATO would predict that these four states, having democratized and adopted a slew of reforms as part of both NATO and EU accession processes, would be eager to complete their transformation, becoming indistinguishable from the Western European states that they sought to emulate. Poland, and the Baltic states had every incentive to display model behavior and to conform to the expectations of cooperative security, as spelled out in the previous section. This would be especially important vis-à-vis their relationship with Russia, which Europe now viewed as a partner rather than a foe. Thus, the constructivist argument would lead one to expect that the Baltic countries and Poland would need less and less reassurance over time. Their transformation should include leaving the past behind, fully embracing their new security identity as NATO member states rather than continuing to bring up historical grievances.

Unresolved grievances

But the Baltic states and Poland have not needed less reassurance since their accession to NATO, despite a layered regional security architecture that includes European, NATO, and US assurances. These states, as well as their fellow CEE states, have expressed a preference for Atlanticism, meaning that they prioritize a strong US-led NATO over European-led security initiatives. The extent to which these states desired to be mainstreamed into the rest of Europe was moderated by the fact that they preferred Washington over Paris and Berlin for security and defense matters. Most famously, as NATO’s cohesion was crumbling over the US’ decision to invade Iraq in 2003, the Czech Republic, Hungary, and Poland (the Baltic states were not yet NATO members) supported the war even though France and Germany opposed it (Zaborowski 2003, 4). Fears of abandonment were certainly part of their rationale, and these fears were further exacerbated by the 2008 Russo-Georgian war and Russia’s 2014 annexation of Crimea. CEE states’ stance within NATO and their Atlanticist strategic culture betrayed an attachment to collective defense and deterrence, even as the Western European countries sought to push these concepts to the background throughout the 1990s and 2000s, including by avoiding collective action on the Georgian-Russian war. NATO only made plans to bolster deterrence on its Eastern flank when Russia presented the fait accompli of Crimea’s annexation. During the same period, the Baltic states and Poland acted pragmatically, supporting US-led and NATO operations in Iraq and Afghanistan to improve their standing within NATO in the hopes of soliciting more favorable responses to their requests for reassurance (Waszczykowski 2008; Eesti Paevaleht2004). CEE states were vocal about the dangers of investing in out-of-area missions at the expense of NATO’s traditional focus on collective defense and deterrence, wanting to re-emphasize the centrality of the Article 5 pledge (Matlary and Petersson 2013).

Despite learning the rules of the NATO bureaucracy and reforming their defense institutions and processes accordingly, Poland and the Baltic states clung to their survival mindset. In other words, learning the ropes did not fundamentally change their security identity. As Maria Mälksoo (2006, 277) puts it, ‘The quest of the Baltic states for membership in the EU and NATO has been the politics of survival par excellence, aimed at securing Western security guarantees against historically aggressive and unstable neighboring Russia.’ Poland and the Baltic states’ anti-Russian stance was not unprovoked. During the debates over NATO enlargement, Russia stated that the Baltic states becoming members of NATO represented a redline and deployed obstructionist tactics to prevent the alliance’s enlargement to the east (Asmus and Nurick 1996). Russia had retrenched from its former empire and now had few tools at its disposal to prevent its former allies and republics from joining the West (Wohlforth 1994/95). Russia’s policies toward the Baltics and Poland employed, what Blank (1998, 50) calls a ‘bullying tone,’ whether the disputes were unresolved border issues along with Russian-speaking minorities and corresponding citizenship laws in the Baltics or, with Poland, the Kaliningrad Corridor proposal, which was summarily rebuffed (Klimiuk 1996). Although the Russians acted as spoilers to stall these countries’ attempts to join NATO and, later, to undermine their position and standing within the alliance, the new members did not opt for the best practices of cooperative security and instead favored threat over conciliation (Blank 1998, 52). Opportunities to participate in regional security initiatives with Moscow, even when they involved other states like Sweden and Finland, were not seriously entertained, nor were opportunities to work on mutual confidence-building measures (61–62). Russia might have been more inclined to accept the NATO enlargement project if states like Poland and the Baltics had not made abundantly clear that they wanted to join NATO to distance themselves from Russia (Rupp 2000, 170).

Within these countries’ foreign and defense policies, the limits of NATO’s powers of socialization were palpable. Despite their desire to rejoin Europe, Poland and the Baltic states were advocates of stronger deterrence measures against Russia, in terms of both conventional and nuclear capabilities. This created a gap between Eastern and Western perceptions of threat within NATO. As Viljar Veebel (2018, 6) notes, ‘Over the decade when Estonia and Latvia were making preparations to join NATO, the alliance itself and its visions and perceptions toward Russia had transformed. Accordingly, in 2004 the two neighboring countries didn’t join the same organization they were expecting to join in the early 1990s, i.e. an organization whose primary focus was collective defence.’ The improved sense of security that NATO membership should have brought was offset by constant fears of Russian resurgence (Mälksoo 2006). These countries’ fears of abandonment were rooted in references to the past, whether it was the Munich Agreement, the Molotov-Ribbentrop Pact, or the Yalta agreements. According to Zaborowski (2003, 6), this is a recurrent point in discussions about Polish strategic culture, where ‘an enduring facet of Polish identity [is] being victims of West European pacifism.’ This is also true with regard to the Baltic states’ strategic culture, shaped by unresolved grievances against Russia (which has not attempted to right past wrongs) and a persistent fear that their European allies could at any moment make backdoor deals that would disadvantage them. To take two examples, the Northern European Gas Pipeline project between Germany and Russia was of deep concern to the Baltic states; and when Latvia was to play host to the NATO summit in 2006, President Vaira Vike-Freiberga tried to prevent Russian participation and made references to its status as a traditional foe (Karabeshkin and Spechler 2007). Whereas states farther away from Russia, like the Czech Republic and Hungary, were more able to think of Russia as potential partner, despite concerns over Russian information operations and propaganda, Poland and the Baltics wanted closer cooperation with Europe, but not with Russia. In this way, they did not conform to the expectations of the rest of Europe.

Deterrence above all else

This division was apparent on the topic of collective defense, as well as conventional and nuclear deterrence. Bruno Tertrais (2008, 4) noted that some NATO states were more eager for US nuclear assurances than others, referring to the CEE states. Poland and the Baltics decided to play it safe and favor the status quo when it came to NATO’s nuclear forces. Whereas, as best described by Yost (2009, 760), ‘the role of the alliance’s nuclear posture as a ‘hedge against Russian backsliding’ is generally not explicitly articulated in public statements by NATO or its member nations in part because of the interest in promoting cooperation with Russia,’ the Baltic states displayed overt support for the assurance role played by US nuclear forces in Europe, in case Russia returned to an aggressive stance. Many Western European states did not want to use the alliance’s nuclear forces as a hedge against possible Russian aggression and in fact were willing to do away with NATO’s nuclear forces altogether. The Baltic states and Poland made clear that they opposed the removal of US nuclear weapons from Europe, though they expressed doubts about the credibility of extended nuclear deterrence more generally, as explained by Urbelis and Paulauskas (2008, 99): ‘For the United States, the United Kingdom or France to prove to other nations that they are ready to risk nuclear holocaust for the sake of the Baltic states is extremely difficult.’

Nuclear extended deterrence, however, was never enough to assure CEE states. As Alexander Lanoszka (2018, 5) argued, ‘Allies tend to believe that in theatre conventional military deployments are necessary for bolstering commitments to extend deterrence.’ These conventional military deployments would only come in 2017 in the form of US assets and multinational battlegroups under the banner of NATO’s enhanced Forward Presence (eFP). By contrast, forward-deployed nuclear weapons are an ineffective reassurance tool. The US weapons stationed in Europe were a symbol of the transatlantic bond and were a residual deterrence capability from the Cold War. Some NATO allies (even those with US B-61 nuclear weapons on their soil) saw them as a liability, as was apparent in the lead up to the Chicago Summit in 2012. All NATO CEE states wanted to preserve the nuclear status quo, not because they viewed nuclear weapons as vital for their security, but because it was not clear what would replace them. They did not want to risk further US retrenchment. Though US nuclear weapons presented no clear military benefit at the time, they were better than nothing (Horovitz 2014).

Fears become reality

NATO’s priorities in 2020 look quite different than they did in the 1990s and 2000s. Individual Baltic countries and Poland had collected mounting evidence against Russia to make the case to NATO that deterrence and collective defense needed to be reprioritized. The Russian cyberattack on Estonia in 2007 and the Russo-Georgian war in 2008, however, had not turned the tide. It took Russia’s annexation of Crimea in 2014 to give Poland and the Baltic states what they had wanted all along, but could not get because of NATO’s attachment to and political incentives in favor of the cooperative security mindset: a greater alliance presence in northeastern Europe. NATO took decisive action in launching eFP after the 2016 Warsaw Summit. The eFP mission currently involves four battlegroups in the Baltics and Poland. Four NATO member states have volunteered to act as framework nations for each of the four multinational battlegroups. The host nations (Estonia, Latvia, Lithuania, and Poland) have integrated these lead countries and troops from other contributing countries into their national force structures. All work and train together under a common NATO flag (von Hlatky 2018). US troops deployed first, in Poland; the rest followed, with the UK, Germany, and Canada each leading one of the three other multinational battlegroups. The mission has been called a tripwire force, and although these battlegroups could not halt or push back a massive Russian advance in the Baltics (the combined force level of eFP barely reaches 5000 troops), their presence is a credible warning to Moscow that the alliance will defend the territories of its easternmost members if necessary. The presence of additional US troops in Poland (outside of the eFP framework) further raises the cost of a potential Russian incursion.

In addition, the Baltic states and Poland have increased their defense spending. A look at NATO’s latest annual report shows that the Baltics and Poland are among only seven countries that have reached the defense spending goal of 2% of their gross national product (NATO Public Diplomacy Division 2019). They are bound by the view that Russia poses a real conventional threat to their territorial integrity. Indeed, there are a plethora of reports and wargames on how to protect the Baltic states and the Suwałki Gap in particular, which is on the border of Poland and Lithuania (Petersen et al. 2018; Shlapak and Johnson 2016). But although it is easy to group Poland and the Baltic states together, given the acute threat from Russia that they face, their defense capabilities are vastly different (Lanoszka and Hunzeker 2019). The Baltic states have smaller economies and populations, resulting in modest defense budgets and armed forces with limited size and equipment. But conscription and the standing up of volunteer militias have compensated for this weakness as the Baltic states improve their territorial defense posture. NATO also fills some gaps. The Baltic states benefit from NATO’s Baltic Air Policing mission to secure their airspace, and Poland has consistently contributed its fighter jets to assist in this mission (NATO 2018).

To summarize, although NATO’s PfP and membership process served to professionalize armed forces from diverse backgrounds (including states that were attempting to shed their Soviet legacies) and foster a common doctrine, it did not necessarily address new members’ security concerns. In fact, though these states joined for preventive deterrence, NATO’s transformation toward a more global security organization, rather than a defensive alliance, exacerbated new members’ need for reassurance. Only after CEE states’ fears were realized did NATO address these concerns concretely with the deployment of multinational battlegroups in 2017, following the 2016 Warsaw Summit. The annexation of Crimea in 2014 changed the terms of the debate for NATO. The contrast between NATO as a collective security organization and NATO as an alliance predominantly focused on collective defense became less stark. Even NATO’s Nordic partners, which clearly favored the former model, had to rethink their relations with NATO.

Collective security versus collective defense: NATO’s partners

Despite fundamental differences with CEE countries, Finland and Sweden offer interesting points of comparison with them in the way that they adapted to Europe’s post-Cold War environment. Both Nordic countries are longstanding and well-respected democracies that did not need any socialization in matters of domestic politics. Both also embraced peacekeeping and humanitarian intervention long before 1990; have defined themselves as neutrals or non-aligned (and as such have stood outside the larger European and Atlantic securities community since 1945); and have been active members of international organizations, promoting the principles of cooperative security, peace, and disarmament (Ingebritsen 2002; Chaney 2017, 23–38). The corollary of neutrality, of course, is the capacity to defend one’s own territory independently; Finland and Sweden embraced the Total Defense model during the Cold War. Sweden was, on paper at least, able to mobilize almost 10% of its population (800,000 troops). Until the end of the 1980s, Finland’s territorial defense also rested on its ability to mobilize its citizenry in case of war. Close to 700,000 soldiers could mobilize if necessary (18% of Finland’s population). Up to 1990, the Finnish defense budget represented 2.1% of its gross national product, a higher figure than for most NATO members (Juusti and Matthews 1990, 86).

Public support for neutrality and a non-aligned foreign policy were strong in Finland and Sweden throughout the Cold War. This being said, Swedish elites were much closer to NATO than it seemed for most of the Cold War. The Swedish government was counting on help from the West in case of war and had secretly authorized the military to make preparations facilitating wartime military cooperation with NATO. Finland’s security policy, for its part, was not strictly neutral. Sharing a 1300-km-long border with Russia has drawbacks. Finland has thus traditionally adopted a posture of strategic accommodation with Russia, seeing that as the best bet to guarantee its independence and territorial integrity. To a certain extent, maintaining a cautiously friendly relationship with Russia is part of the Finnish DNA. Both Sweden and Finland’s strong stances in favor of neutrality and internationalism on the world scene raise the question of what impact the end of the Cold War had on their foreign policies after 1990, particularly as they related to NATO and European security. Specifically, to what extent did NATO influence the security mindset of the Nordic neutrals?

Europeanization of Sweden’s and Finland’s security and defense policies

The events of 1989–1991 triggered a sea change in Sweden’s and Finland’s security policies. Both rapidly applied for membership in the EU with significant public support, becoming full members in 1995.Footnote 2 This was primarily an economic choice, but neither neutral could ignore the security implications of its decision. The EU had just launched the European Security and Defense Policy in Maastricht, opening the door to increased defense cooperation among its members. The Petersberg Declaration (1992), in particular, defined a number of tasks that could be undertaken by the EU in the area of peacekeeping, crisis management, and humanitarian or rescue operations. In view of their longstanding policy of support for peacekeeping, both Sweden and Finland were open to participating in UN-sanctioned EU operations, especially the humanitarian and non-military kind. Preserving peace, strengthening international security, and promoting democracy, the rule of law, human rights, and fundamental freedoms had a natural appeal for both countries in a post-Cold War environment.

In addition to their involvement with the EU, Helsinki and Stockholm also drew closer to NATO. They joined the PfP when it was established in 1994 and adhered to the Planning and Review Process (PARP) which aims to promote the development of forces and capabilities by partners the following year. The PfP was, on the one hand, compatible with their status as neutrals because it did not involve membership in NATO or direct participation in the alliance’s common defense plans. On the other hand, partnership gave both neutrals a say in the shaping of the new European security environment. The PfP also emphasized dialogue and cooperation with former enemies, another key dimension of the cooperative security mindset. Moreover, PfP status offered the opportunity for Finland and Sweden to develop their armed forces and ensure that they were interoperable with NATO’s. As military partners, Finland and Sweden have also participated in almost every NATO mission since the end of the Cold War, from the Implementation Force (IFOR) and Stabilization Force (SFOR) in Bosnia, and Kosovo Force (KFOR) to the International Security and Assistance Force (ISAF) in Afghanistan (Dahl and Järvenpää 2013, 128; Cottey 2013, 460).

The most significant difference between Sweden and Finland lies in their defense posture. After the Cold War, the Swedish government made the radical choice to transform its armed forces into a small peacekeeping force whose only purpose was to intervene abroad in the framework of multilateral operations. The Finnish government opted for a more prudent course. The Finns never believed that history ended in 1989 (Kunz 2018, 7). Despite the end of the Cold War, a majority of Finns declare themselves ready to defend their country in case of war (Finnish Security and Defence Policy2001). Finland, accordingly, never abolished conscription. It still can mobilize 285,000 soldiers, which is remarkable for a country of barely 5 million inhabitants (Sweden has 10 million). It remains proud to play a bridge-building role between Russia and the West (Mouritzen 2019, 11). For Finland, Russia is ‘a neighbor to whom one has to talk (authors’ translation)’ (Kunz 2018, 7). This is all the more important because Finland and Russia are economic partners.Footnote 3 Finnish security policy was prudent, realistic, pragmatic, and flexible during the 1990s and early 2000 and, as such, better prepared than Sweden’s for the events of 2008 and 2014, which would disturb both countries’ cooperative mindsets.

Sweden and Finland after the Ukraine Crisis

The Georgian and Crimean crises, combined with the drastic change in Russian behavior from 2008 to 2014, were traumatic for the Baltic and Scandinavian countries, as well as Poland. Unexpectedly, Russia, which had been considered a partner and peaceful neighbor by Sweden and Finland, quickly became an aggressive great power eager to reassert its influence on what it considered its neighborhood, namely the Baltic region, the Caucasus, and Ukraine. The number of provocations and threats against Nordic countries, including Sweden and Finland, and the Baltic states increased markedly. One of the most famous examples of Russia’s provocations was the appearance of a submarine suspected to be Russian near Stockholm in the fall of 2014. Another case was the Russian military exercise held in March 2015 that simulated a landing on the Swedish island of Gotland and the Danish island of Bornholm. Russia also launched a series of cyberattacks against Estonia in 2007 and threatened to target Denmark with nuclear weapons if it participated in NATO’s Ballistic Missile Defenses. One of the preferred tool of Russian statecraft is ‘active measures’: political warfare waged with disinformation and agents of influence in the media and on the Internet. The ultimate goal of Russian policy toward Sweden, Finland, and the wider Scandinavian and Baltic area seemed to be to intimidate regional actors, increase Russian influence, and minimize NATO’s presence in the region (Czarny 2018, 245–246; Kragh and Åsberg 2017).

The reemergence of great power politics in the region has required Nordic states to review the fundamentals of their security and defense policy. This was particularly important for Sweden, which had, for all intents and purposes, been dismantling its defense establishment since the mid-1990s. Underlining the clean break in their security policies, the four Scandinavian defense ministers issued a joint communiqué in April 2015, stating that Russia’s actions in Crimea were ‘unacceptable and in breach of international law.’ Russia, in their view, was rapidly becoming ‘the most important challenge for European security’ (Kunz 2018, 5; also Søreide et al. 2015). To confront the Russian threat, the Swedish government adopted a new defense plan in 2015, covering the period 2015–2025. It announced an increase in defense funding of $2 billion over 4 years and reinstated conscription in 2018. Although the 2015–2025 defense plan represents a break from the recent past for the Swedish armed forces, it is far from a return to the Total Defense concept of the Cold War. For its part, Finland has decided to increase its investments in several major defense programs, notably for its air force and navy. But overall the Finns rely, as they have done in the past, on their mobilization capacity and a strong reserve of a quarter million personnel. Sweden and Finland have increased their efforts to promote regional defense cooperation between the Scandinavian and Baltic states through the Nordic Defense Cooperation (NORDEFCO), launched in 2009. Sweden and Finland have also reinforced their link to NATO and the USA. They regularly join NATO countries in military exercises and maneuvers. Stockholm and Helsinki also signed a number of host nation support agreements in 2014. These agreements give a legal framework to NATO forces if they need to be stationed on Swedish or Finnish territory. Additionally, Sweden and Finland participate in the Enhanced Opportunities Partnership program, which, among other things, offers the possibility of accelerating the procedure to become a NATO member in case of need. Swedish and Finnish ministers attend NATO’s defense and foreign affairs ministerial meetings on a regular basis. Indeed, and as noted by Mouritzen (2019, 14), both neutrals are so close to the alliance that they have earned the nickname ‘NATO’s virtual members.’

What should be clear from this discussion is that NATO’s influence on security and defense-policy developments in Sweden and Finland has been limited. Sweden and Finland adopted a cooperative mindset in parallel to, not because of, the alliance; they prioritized the EU over NATO in the formulation of their foreign and defense policy; and they shifted gears in 2014 as the result of a changed security environment. Both countries, which had strong incentives to buy into NATO’s collective security model, have certainly realized that power politics are back in the Baltic area and have moved away from their post-Cold War cooperative security mindset. The Finnish case is probably the most clear-cut. To echo Gebhard (2017, 260–261), framing its new relationship with Western Europe, the EU, and NATO as a coming home, a return to a previously suppressed cultural identity, Finland remains more of a pragmatic adapter. As we have shown, the Finns participated actively in most of NATO’s and the EU’s multilateral operations. An acute awareness of the Russian military presence dictated most Finnish strategic choices after the end of the Cold War. As previously discussed, Finland has maintained a dialogue with Moscow and keeps the relations between the two countries on friendly terms.

The case of Sweden is somewhat more complex because of the dual nature of its security policies (Christansson 2017, 40). On the one hand, Sweden has traditionally defined itself as a neutral power in international relations. These policies have publicly been defined as central to Swedish identity since the early Cold War. On the other hand, many Swedes—especially those on the center-right of the political spectrum—realized that neutrality was only viable with the military backing of the West, namely the USA and NATO. To what extent has this double identity evolved since 1990? Sweden rapidly embraced the concept of cooperative security, which became the lodestar for Swedish security and defense policy in the 1990s and early 2000s. Authors like Pernille Rieker concluded in the early 2000s that Sweden’s security identity was in the process of changing (Rieker 2004, 384–385). The reemerging tensions between Russia and the West since 2008, however, have stopped this trend in its tracks and led to a major shift in Swedish security policy. Territorial defense and the maintenance of a regional balance of power are again in the forefront of Swedish strategy, as opposed to multilateral peace operations and cooperative security. NATO did not and could not offer a mechanism to prevent or resolve tensions on the European continent, whether for states that operated as part of the alliance or for the Nordic countries that closely cooperated with it.

Discussion and conclusion

After the Cold War, NATO had an opportunity to redefine the security mindset of its member states along cooperative security lines, a change that became wrapped up in debates over enlargement (Epstein 2005). In this article we showed that, contrary to constructivist expectations, the post-Cold War socialization of NATO states and partners in the Baltic Sea region did not fundamentally transform their security mindsets. As NATO adapted to the post-Cold War environment, two models emerged: one privileging its transformation to a collective security organization, where cooperative norms would prevail, and the other clinging to collective defense and deterrence calculations. NATO’s new CEE members remained on guard against a resurgence of the Russian threat and pursued collective defense, understanding that paying lip service to cooperative security was the price of admission. These states’ identities and security mindsets remained unchanged with NATO accession.

This article surveyed the NATO literature on enlargement and considered various propositions to help explain the alliance’s post-Cold War transformation. If socialization had indeed been powerful enough to transform the security mindsets of new members, reassurance needs should have decreased with accession. One would also expect to see a corresponding shift in the tenor of new members’ foreign and defense policies to reflect NATO’s emphasis on cooperative security as opposed to traditional deterrence and defense as embodied by the alliance’s collective defense pillar.

We then compared two groups of states: those that joined NATO in the post-Cold War period (CEE states) and those that could have joined but decided not to (Finland and Sweden). These states can be said to share NATO’s liberal and democratic values, as strengthened by the alliance’s accession process (CEE states), or having evolved quite independently from it (Finland and Sweden), but whether these states were inside or outside of NATO, they did not transform their security mindsets. At best, they adjusted their foreign- and defense-policy proclivities to respond to the level of threat within their immediate security environment.

Our conclusion is that cooperative security as an alternative security lens to balance-of-power politics was a flash in the pan. To be sure, NATO’s influence in CEE countries was considerable and led to a monumental change in military practices. However, these countries did not adopt new cooperative security identities or change how they assessed the security environment. New members saw the NATO socialization process as strengthening them within a balance-of-power mindset that ultimately set back NATO’s cooperative security project. The establishment of a common security identity beyond the performance of common practices has therefore been overstated.

This transformation project may also have had unintended consequence. Because NATO was unsuccessful in having its new members adopt the cooperative security mindset, it became even harder to convince Russia to do the same. Ultimately, enlargement and the experience of cooperative security made the CEE states nervous about the credibility of their security guarantees, which pushed them to seek greater security assurances in an era when NATO was trying to convince them such assurances were no longer necessary. The alliance’s insistence on promoting norms of self-restraint and cooperative security while downplaying its traditional focus on collective defense and deterrence may have undermined the credibility of its commitments to new allies, hardening their stance toward Russia. NATO is simultaneously a political decision-making forum, an alliance, and a multinational military academy. Once former Warsaw Pact countries achieved membership, however, traditional security interests overshadowed the rest.