Yet NATO not only survived the Cold War but expanded into the former Warsaw Pact and Soviet space. Over just 25 years, the alliance doubled its membership roster from 16 to 32 states while adding nearly as much territory that the US was obligated to help protect as the original 1949 alliance. Crucially, this was a primarily American project: although many of the states to which NATO expanded wanted into the alliance, most of the existing allies opposed expansion and had to be cajoled and pressured by Washington into accepting enlargement. Meanwhile, keeping NATO’s door open remains central to the alliance’s official policy and a cardinal principle in Washington foreign policy circles. The question becomes: from an American point of view, was this a wise move?
Proponents of enlargement think so. From this perspective, enlargement provided the United States four benefits. First, an enlarged alliance is said to have given NATO a new purpose after the Cold War and ensured the durability of the postwar “liberal international order.” Second, proponents allege that enlargement helped liberalize post-communist states throughout Central and Eastern Europe, thus ensuring liberal democracy and capitalism flourished throughout the area. Relatedly – third – enlargement may have limited post-Cold War instability and conditions that could produce a wider conflict in CEE born of competition among states in the area and/or between Germany and Russia for regional influence. Finally, NATO’s post-Cold War expansion is said to have blocked the re-emergence of a Soviet-type hegemon by dissuading and deterring Russian revisionism.
None of these claims withstand scrutiny.
Claim 1: Enlargement Kept NATO in Business
The notion that NATO enlargement was valuable because it kept NATO in business during “a time of peace” (to quote Madeline Albright) puts the cart before the horse. Alliances are not valuable in themselves – they are valuable because of how they serve a state’s interests. To this point, the United States was happy at several points during the Cold War to threaten the future of NATO if its allies did not defer to American concerns independent of what the allies wanted; tellingly, for example, Eisenhower as president threatened an “agonizing reappraisal” of the US commitment to Europe if France did not entertain the possibility of German nuclearization. By the same token, the notion that enlargement helped keep NATO alive and so protected the postwar liberal order elides the fact that, if the liberal order is valuable and other states deeply committed to its tenets, then other actors would have been committed to its preservation and defense. By this claim’s own logic, enlargement would be superfluous.
Claims 2–3: Enlargement Helped CEE Liberalization and Stopped Instability
Different problems emerge with claims surrounding NATO’s centrality to Central and Eastern Europe. In terms of liberalization, NATO – as a military alliance – was, is, and remains poorly suited as a liberalism promotion vehicle. To the extent external actors can influence domestic trajectories, it requires constant time and attention. Once a state joins NATO, however, the alliance ceases to have tools for applying this pressure – there is no NATO eviction mechanism, and to threaten abandonment of a single state because of domestic problems is to invite questions over the alliance’s credibility. Indicative of the problem, we have seen meaningful democratic backsliding among NATO members such as Turkey, Poland, and Hungary with few consequences. Furthermore, it is also why scholars who have studied liberalization in Central and Eastern Europe ascribe more of the trend to the European Union – an institution optimized for monitoring and adjusting to members’ behavior – than to NATO as such.
Conversely, it may be true that enlargement helped dampen some forms of regional instability, in particular by reducing former Soviet clients’ need to arm for self-defense and so limiting the risk of insecurity spirals. Even here, however, it is not obvious that NATO was the only vehicle to solve the problem. After all, multilateral options such as NATO’s Partnership for Peace could have provided similar forms of reassurance, with few of the downsides – discussed below – attendant to formal membership. Meanwhile, it is hard to argue competition between Germany and Russia would have erupted if not for enlargement: with Russia in economic and military malaise throughout the 1990s-2010s and Berlin focused on knitting the former East and West Germany together, there was limited opportunity for regional security competition.
Claim 4: Enlargement Deterred Russia
This last point also underscores problems with claims that NATO enlargement helped deter Russian revisionism. At root, with Russia a faint shadow of the USSR, Russian opportunities for aggression for most of the post-Cold War period were limited. Indeed, it was only when an enlarged NATO arrived on Russia’s border that Moscow was able to issue plausible military threats against the alliance. Moreover, it is important to remember that Russia under Boris Yeltsin sought Russian liberalization at home and cooperation abroad; its motivations were anything but hostile. Although the evidence is less certain, Vladimir Putin also seems to have been less revisionist – at least early on – than many see in retrospect. After all, if Putin’s Russia were truly revisionist and held in check only by NATO, then one would have expected Moscow to aggress before NATO expanded to states such as Latvia and Estonia, as well as taken earlier and more consistent action against states such as Ukraine and Georgia than actually occurred. In any case, even if Russia had proven revisionist in a world where NATO enlargement never happened, the presence of former Soviet clients eager to guard their independence suggests it would have been both possible to create a balancing coalition outside NATO auspices and taken a long time before Russia posed the sort of hegemonic threat that might imperil US security. Put simply, NATO expansion was not necessary even if the goal was to block Russian aggrandizement.
Drawbacks to Enlargement
In short, enlargement did not produce the positives that proponents posit. Still, the issue goes beyond just the absence of advantages – in fact, enlargement has meaningfully damaged US national security. Several problems stand out.
The Bleeding Frontier
First, NATO expansion has tied the United States to a host of states which add little to US security yet leave US policy flexibility hostage to local dynamics with few exit options. Strategically, regardless of whether one believes the United States ought to try to dominate European politics itself or more narrowly block the rise of a European hegemon, it is difficult to argue that states such as Poland, Hungary, Romania, and Latvia are central to such an effort. In terms of population, economics, military potential, and diplomatic heft, these countries do little to bolster US power and influence in Europe. Politically, their liberalization and commitment to free-market capitalism—though good for those states—is irrelevant to US national security. Even in the context of European liberalism, one should recall that liberalism flourished throughout much of the continent during the Cold War despite the presence of communist autocracies. And while it might be detrimental to US national security should another state dominate Central and Eastern Europe, the likelihood of such a challenger emerging is virtually nil given Russian weakness (clearly demonstrated in its poor showing in the Russia-Ukraine War), regional actors’ desire to protect their own independence, and the presence of capable states in Western Europe.
By enlarging NATO to these states, however, the United States has been pushed to treat their concerns as central to US interests – enlargement acted as a transmission belt that links allied concerns to US policy. In the 1990s, concerns with regional instability due to the Balkan Wars at a time when NATO was preparing to enlarge helped pull the US into those conflicts. In the 2000s-2010s, concerns from new NATO members and aspirant NATO members that Russia might one day aggress again provided momentum for continued enlargement and moving the alliance further into CEE. Since Russian-Ukrainian tensions spiked after 2014, calls by vulnerable allies such as Latvia and Estonia for protection have compelled the United States to consider a range of costly schemes to defend states whose security is difficult to ensure due to geography. If confrontation with Moscow continues, these demands are likely to increase even as the solutions may grow in cost and escalatory potential. Meanwhile, because US leaders often put a premium on ensuring the credibility of NATO’s security guarantees – in part to keep enlargement itself a credible policy – there are few options for ignoring allied pressure. Had NATO not enlarged, security concerns in Eastern Europe would have had more limited impact on US defense planning and cost.
Allied Cheap Riding and Reckless Driving
Second, enlargement has likely encouraged allied cheap-riding and reckless-driving in ways that harm US security. On the one hand, with NATO having gone from 16 to 32 members, it becomes easier for any one country to under-invest in its defenses in hopes that some other state will pick up the slack. Enlargement transformed the alliance from a primarily Western European enterprise to a continent-wide grouping, which only reinforced this problem by limiting the extent to which NATO members share similar threat perceptions; it is not hard to understand why, for example, Spain or Italy might perceive Russia as less threatening than Poland and so prepare for different security missions. With the US as the primary booster of enlargement, however, and having staked much of its foreign policy on the alliance, it often falls to Washington to make up the difference in allied investments and ensure the alliance is strategically viable. Thus, not only has US defense spending been higher than other allies, but the US has been called upon both in peacetime – for instance, to reinforce Eastern Europe following the 2022 Russian invasion of Ukraine – and in wartime – for example, during the 2011 Libyan intervention – to compensate for European shortfalls.
Some of the alliance’s post-Cold War members have also likely engaged in reckless driving due to the extra margin of security provided by NATO membership. The Baltic states, for example, have often taken the lead in challenging Russian foreign policy despite their evident concern with possible Russian aggression. It is difficult to explain these contradictory trends without NATO security guarantees: absent NATO membership, one expects these states to look to their defenses without otherwise risking the very confrontation they fear. Polish policy during the Russia-Ukraine War provides another example: without NATO membership, one would not expect Warsaw to be so forward-leaning in calling for intervention in a conflict with a conventionally superior nuclear power, nor to take steps on its own (e.g., offering Ukraine bilateral security guarantees) that increase the risk of involvement. Because such reckless driving can lead to conflicts and confrontations involving NATO allies, they provide an ongoing risk of US entanglement in situations where the US, left to its own devices, would not be involved.
Antagonizing Moscow
Finally, enlargement contributed to worsened relations with Moscow. There are many reasons that US relations with Moscow soured over the last three decades, just as there are multiple drivers of Russia’s ongoing aggression in Ukraine that has put US-Russian relations in a deep freeze. NATO enlargement, however, played an outsized role. When enlargement was first entertained in the 1990s, no less a figure than Russian President Boris Yeltsin warned that moving NATO eastward would violate assurances given against enlargement made during the 1990 negotiations over German reunification, empower Russian nationalists, and ultimately reduce the prospects for a stable post-Cold War peace.
Then-President Clinton believed that Russian opposition could be variously ignored due to Russian weakness, overcome through engagement, or transformed through Russian democratization. Still, Russian opposition was real and pronounced: in the 1996 Russian election, Yeltsin’s opponents made the then-possibility of NATO enlargement a centerpiece of their campaigns, and Yeltsin himself resisted enlargement within the limited options available to Moscow at the time.
After enlargement began, meanwhile, both Yeltsin and Putin underscored that the policy challenged Russian interests by limiting Russian influence in European security affairs. As Putin put it in 2007, enlargement represented “a serious provocation that reduces the level of mutual trust.” Despite these concerns, however, enlargement continued – indeed, with the Bucharest Summit’s decision to promise NATO membership for Ukraine and Georgia, it began to involve areas that, as US ambassador to Russia Bill Burns warned at the time, were “the brightest of all red lines” for Moscow. In turn, it is not surprising that the Russian invasion of Ukraine – tragic, unwarranted, and unjustified as it is – erupted when (1) Moscow grew concerned that Ukraine was taking practical steps that would further tie it to the alliance, and (2) US diplomatic efforts to avert an invasion refused to include discussion of NATO enlargement. Ultimately, even if some tensions with Moscow were inevitable as Russia recovered from its 1990s nadir, NATO enlargement exacerbated the scope and intensity of the problems while limiting US options for resolving tensions.
Conclusion: The Future of Enlargement
Taken together, NATO enlargement has had limited benefits for the United States yet carried a number of costs. Against this backdrop, the prospective future enlargement of the alliance to Ukraine – a remarkably popular policy option in Washington – is not in the United States’ interest. Although NATO’s 2024 Washington summit pledged an “inevitable” path for Ukrainian membership, making Ukraine a member would bring in a state of limited strategic value with uncertain domestic institutions, and one which Russia both considers a vital interest and is clearly willing to fight for. Conversely, the United States has demonstrated since February 2022 that it is unwilling to risk war for the sake of Ukraine, recognizing – as President Biden put it – that doing so could bring on “World War III.” Expanding the alliance to Ukraine would only deepen NATO-Russian hostility while raising profound questions over the credibility of NATO’s security guarantees to Kyiv. It is distinctly possible NATO and the United States would face simultaneous military and credibility crises.
Three decades after it began, it is time move away from NATO enlargement. This is not a bad thing, as policies can and should be adjusted in response to changing international conditions. NATO enlargement began when the post-Cold War world was coming into focus and the United States’ unipolar era made many policies look relatively cheap and easy to pursue. Those conditions are no longer with us, and the costs and benefits of enlargement have proven different than what was expected. A course correction is in order
