Table of Contents

Russia’s annexation of Crimea in 2014 and its subsequent involvement in the war in eastern Ukraine have caused deep concern in the capitals of North Atlantic Treaty Organization (NATO) members. In the 2016 Warsaw Summit Communiqué, NATO labeled Russia a “challenge [to] the Alliance” and “a source of regional instability.”1 These concerns reflect the reality that a war between Russia and NATO, although unlikely, is not unthinkable anymore. The risks of tensions escalating in general or in a crisis are particularly high in the wider Baltic region, which includes the three Baltic states (Estonia, Latvia, and Lithuania), Poland, parts of western Russia, and the adjacent waters of the Baltic Sea.2

Russia’s annexation of Crimea in 2014 and its subsequent involvement in the war in eastern Ukraine have caused deep concern in NATO capitals.

An underlying challenge is that Russian interests and strategy toward the region are ambiguous and leave much room for speculation and misinterpretation. Specifically, NATO allies cannot be sure what Moscow’s intentions toward the Baltics and the alliance are. Does it aim to merely intimidate these countries by various threats? Or does Russia plan to invade? Particularly prevalent in the Baltic states and Poland—all of which have borders with Russia—these concerns have prompted NATO to reassure its easternmost members with a number of limited defensive measures, most prominently by agreeing to deploy four multinational battalions to the three Baltic states and Poland to deter eventual Russian aggression.3 Meanwhile, Moscow strongly denies any malign intentions toward NATO, and instead points to the alliance as a threat to its own national security.4

As a consequence of these ambiguities, it is possible that NATO may be overestimating the threat emanating from Russia, and the alliance could end up precipitating exactly the kind of security threat that it seeks to avoid. For example, the well-intentioned defensive measures for the Baltic states and Poland that allies agreed to implement at the Warsaw Summit could reinforce legitimate as well as imagined Russian security concerns. Moscow has already denounced NATO’s actions as aggressive and announced retaliatory steps.5 Some NATO members have warned the alliance of doing too much and assert that enhanced defensive measures might only further deteriorate the security situation in the region by raising tensions with Russia.6 As a consequence, both sides may enter a security dilemma that could raise tensions and make conflict more likely, if this is not already happening.

Conversely, it is also possible that NATO may be underestimating the Russian military threat. Russia’s strategy of conflict, as stipulated in its doctrine of new-generation warfare,7 appears to be comprehensive, involving everything from propaganda to potential nuclear use. Failing to identify a sound response that addresses the threat in its totality could be dangerous. For example, NATO’s defensive measures, by being too limited, could lead Moscow to deliberately test allies’ resolve, perhaps even by military means.

Some NATO members argue that the alliance is still not doing enough to credibly deter Russia.8 The geography and the military balance in the region present real challenges to NATO in defending Baltic allies. Russia has a much larger force presence than NATO in the region and, by using land routes, can quickly reinforce equipment and personnel. NATO, by contrast, would have to fly or ship in reinforcements—a much slower process. Additionally, Moscow continues to hold large-scale military exercises based on aggressive scenarios against neighboring states such as Poland, close to NATO’s borders. The latest one—Zapad 2017—peaked in September 2017. Such exercises, some of Russia’s neighbors fear, could be used as a cover for a limited military attack against them.9

Some NATO members argue that the alliance is still not doing enough to credibly deter Russia.

The conventional challenge in Europe is compounded by Russia’s increasingly aggressive behavior in the nuclear realm. On various occasions since 2014, the United States has publicly accused Russia of violating the Intermediate-Range Nuclear Forces (INF) Treaty by developing and, more recently, deploying a ground-launched cruise missile (although Washington has not indicated whether it believes these missiles are designed to accommodate nuclear or nonnuclear warheads or both).10 Furthermore, Russia frequently issues blunt nuclear threats toward NATO allies. For example, in March 2015, the Russian ambassador to Denmark said that if Danish warships contributed radar capacity to NATO’s missile defense system, “Danish warships will be targets for Russian nuclear missiles.”11

All these developments create political (as well as military) problems for NATO. They lead to pressure on NATO to review its own deterrence and defense posture, including its nuclear component, and, perhaps, to formulate more muscular responses. But such a debate—already tentatively taking place at NATO Headquarters—risks eroding unity among NATO allies, which have a wide range of different preferences in the nuclear realm. This erosion of unity could undermine deterrence. A military alliance at odds over its own deterrence and defense posture could be perceived as weak by Russia, making it a potential target for military blackmail and coercion.

Preserving NATO’s unity is, therefore, a key task for the alliance, even more so since Russia’s doctrine of new-generation warfare is challenging NATO militarily and politically in many other respects. All three Baltic states, for instance, are subject to relentless Russian attacks through propaganda, disinformation, and outright hate speech that have become more virulent since 2014.12 These states are home to significant ethnic Russian minorities that receive Russian state-sponsored media almost exclusively. This propaganda deepens existing divides, which date back to the Soviet occupation, between the different populations groups in the Baltics.13 Perhaps Russia does not seek to stoke protests or outright unrest among minority groups. But even if it does not, Moscow’s negative influence nonetheless increases the risk of a domestic crisis in one of the three states, in the wake of which there could be growing domestic pressure on the Kremlin for Russia to come to the aid of Russians living abroad.

Preserving NATO’s unity is a key task for the alliance, even more so since Russia’s doctrine of new-generation warfare is challenging NATO militarily and politically in many other respects.

Even if Moscow is not planning for deliberate aggression against NATO, accidental escalation is another potential risk. Russia has stepped up military brinkmanship vis-à-vis NATO member states since the outbreak of the war in Ukraine.14 In 2016 alone, Russian military aircraft violated Estonian airspace five times and often came extremely close to allied aircraft.15 These actions could result in an accident, potentially killing NATO and Russian service personnel. In the wake of such an accident, tensions could rapidly mount, especially given domestic pressure to retaliate. NATO and Russia might find themselves unable to control the subsequent escalation.

So far, NATO has responded with an incremental approach, focused on collective defense, crisis management, and cooperative security. At its 2014 summit in Wales, NATO emphasized the assurance of allies, particularly those in the Baltic region, who felt most vulnerable.16 By the 2016 Warsaw Summit, the emphasis had shifted to deterrence and defense, as allies set out NATO’s primary responsibility as being “to protect and defend our territory and our populations against attack.”17 By agreeing to deploy multinational forces from sixteen member states to the region, allies aimed to increase the credibility of NATO’s deterrence and defense posture against Russia by trying to convince Moscow that an attack on one would be an attack on all. The Warsaw Summit Communiqué also highlighted a possible cooperative way forward by underscoring political dialogue with Moscow aimed at avoiding misunderstanding, miscalculation, and unintended escalation by means of transparency and predictability.

Indeed, NATO’s deterrence and defense approach still contains loopholes that must be closed. But deterrence alone is ill-equipped to manage the nonkinetic or accidental escalation risks that Russia’s doctrine of new-generation warfare pose. NATO needs a comprehensive, threefold strategy that addresses these risks and takes into account the views of allies in the wider Baltic region.18 As NATO seeks to formulate an effective response to Russia’s policies and actions, the alliance is facing three major tasks: (1) how to calibrate its deterrence measures to prevent deliberate Russian escalation and to assure its easternmost members; (2) how to maintain alliance unity in light of the differing threat perceptions—particularly toward Russia—and defense priorities of the members states; and (3) how to prevent possible inadvertent or accidental escalation with Russia. If left unattended, these challenges will further increase the already high risk of escalation in the Baltic region. The focus should be on what NATO can do now to reduce the risk of escalation in the future, rather than on the separate (albeit important) question of how NATO should try to manage escalation should a crisis occur.

To this end, NATO should close dangerous loopholes in its current deterrence and assurance approach, so as to deter Russian aggression against NATO and prevent Moscow from using deliberate escalation to coerce the alliance. The alliance should also double down on efforts to enhance resilience—that is, increasing the ability of member states to absorb shocks, such as sudden electricity outages or large-scale cyberattacks on corporate networks. NATO must make its societies—in particular its easternmost allies and Russian minorities living there—more immune to Russian destabilization efforts. Finally, by engaging Moscow in talks on risk-reduction measures, NATO should seek to diminish the potential for accidental escalation, especially given the spike in dangerous military encounters. Over the longer term, it is also possible that consultations with Russia could lead to more far-reaching arms control talks about conventional forces in the region.19

Finding the right balance between deterrence and assurance, resilience, and risk reduction will be no easy feat, but could pay dividends if done well. NATO will probably have to make trade-offs. For instance, further emphasizing military responses—perhaps by additional force deployments—could help to solidify assurance of the Baltic states and Poland. At the same time, it might risk alliance unity and could spark, instead of prevent, escalating general tensions with Russia since Moscow might interpret these defensive measures as offensive in nature. Prioritizing risk-reduction measures, meanwhile, could temporarily halt the risk of inadvertent or accidental escalation but might come at the expense of undermining deterrence and assurance. There may also be synergies in addition to the trade-offs. For instance, NATO could couple the real prospect of additional permanent force deployments with an offer of dialogue to Russia. The aim could be to craft a reciprocal arms control arrangement for the region that makes additional force deployments redundant.


The author wishes to thank James Acton in the first place for his always insightful comments and continuous efforts to improve the quality of this report. In no order of the significance of their contributions, this report also benefited from the help of William Alberque, Samuel Brase, Samuel Charap, Toby Dalton, Ryan DeVries, Dave Johnson, Martin Zapfe, the anonymous Baltic and Polish officials and experts who were interviewed, and Carnegie’s whole Nuclear Policy Program team. This research was conducted at the Carnegie Endowment for International Peace in Washington, DC, between September 2016 and September 2017.

Carnegie gratefully acknowledges the support of the Stanton Foundation that made the writing of this report possible.


1 NATO, “Warsaw Summit Communiqué,” press release, Warsaw, Poland, July 8–9, 2016,

2 This report does not directly consider the security of neighboring non-NATO members—namely, Belarus, Finland, and Sweden.

3 For instance, the Polish Strategic Defense Review, initiated in 2016, concludes that “the scale of threats resulting from the Russian aggressive policy had not been adequately assessed in the past.” Poland was thus, according to the authors, facing “the necessity of adequately preparing Poland to defend its own territory.” Polish Ministry of National Defense, The Concept of Defense of the Republic of Poland (Warsaw: Ministry of National Defense, 2017), 6,

4 According to a speech by Vladimir Putin: “Russia has no intention of attacking anyone. This is all quite absurd. . . . It is unthinkable, foolish and completely unrealistic. Europe alone has 300 million people. All of the NATO members together with the USA have a total population of 600 million, probably. But Russia has only 146 million. It is simply absurd to even conceive such thoughts.” Kremlin, “Meeting of the Valdai International Discussion Club,” October 27, 2016,

5 Rishi Iyengar, “Russia Announces New Military Divisions to Counter NATO Deployments in Eastern Europe,” Time, May 4, 2016,

6 For a good overview of the different arguments within NATO, see Jens Ringsmose and Sten Rynning, “Now for the Hard Part: NATO’s Strategic Adaptation to Russia,” Survival 59, no. 3 (June-July 2017): 129–146.

7 New-generation warfare (NGW) is basically a boundless military strategy that includes and targets all military and civilian realms with the goal of coercing the opponent into accepting changes to the status quo (see chapter 2). When referring to NGW, it is probably more appropriate to speak of a “corpus of ideas” than of a full-fledged military doctrine. See Dmitry Adamsky, Cross-Domain Coercion: The Current Russian Art of Strategy (Paris: French Institute of International Relations, 2015), 22, Other Western scholars use the term Gerasimov Doctrine—a reference to the chief of the general staff of the armed forces of Russia, Valery Gerasimov. See Mark Galeotti, “The ‘Gerasimov Doctrine’ and Russian Non-Linear War,” Moscow’s Shadows (blog), July 6, 2014, Again, others have referred to a strategy of “full-spectrum conflict.” See Oscar Jonsson and Robert Seely, “Russian Full-Spectrum Conflict: An Appraisal After Ukraine,” Journal of Slavic Military Studies 28, no. 1 (2015): 1–22. Still others describe it as “strategic deterrence.” See Kristin Ven Bruusgaard, “Russian Strategic Deterrence,” Survival 58, no. 4 (August-September 2016): 7–26; Dave Johnson, Nuclear Weapons in Russia’s Approach to Conflict (Paris: Foundation for Strategic Research, 2016), The term strategic deterrence should not be confused with the more narrow strategic nuclear deterrence relationship between Russia and the United States.

8 Andrius Sytas, “Baltics Need Anti-Aircraft Protection Against Russia, Lithuania Says,” Reuters, July 20, 2017,

9 See Michael R. Gordon and Eric Schmitt, “Russia’s Military Drills Near NATO Border Raise Fears of Aggression,” New York Times, July 31, 2017,

10 See the testimony of General Paul Selva, as quoted in a New York Times article. Michael R. Gordon, “Russia Has Deployed Missile Barred by Treaty, U.S. General Tells Congress,” New York Times, March 8, 2017, For a good backgrounder on the INF Treaty, see Amy F. Woolf, Russian Compliance With the Intermediate Range Nuclear Forces (INF) Treaty: Background and Issues for Congress (Washington, DC: Congressional Research Service, 2017),

11 “Russia Threatens to Aim Nuclear Missiles at Denmark Ships if It Joins NATO Shield,” Reuters, March 22, 2015,

12 See Ieva Bērziņa (ed.), The Possibility of Societal Destabilization in Latvia: Potential National Security Threats (Riga: National Defense Academy of Latvia, 2016),

13 For a good overview of the state of inclusion and potential vulnerabilities of Russian minorities in Latvia, see Žaneta Ozoliņa (ed.), Societal Security. Inclusion-Exclusion Dilemma: A Portrait of the Russian-Speaking Community in Latvia (Riga: Zinātne Publishers, 2016),

14 European Leadership Network, List of Close Military Encounters Between Russia and the West, March 2014 – March 2015 (London: European Leadership Network, 2015),

15 See Michael Birnbaum, “Russian Warplanes Keep Buzzing the Baltics. Here’s How NATO Scrambles,” Washington Post, November 6, 2016,

16 NATO, “Wales Summit Declaration,” Newport, Wales, September 5, 2014, See paragraphs 3, 7, and 52, in particular.

17 See NATO, “Warsaw Summit Communiqué,” paragraph 6.

18 For this report, the author conducted twenty-six in-person interviews with officials and nongovernment experts in Latvia, Lithuania, and Poland in April 2017.

19 Kingston Reif, “Europeans Seek Conventional Arms Talks,” Arms Control Today 47, no. 1 (January-February 2017): 45.