Since launching its full-scale invasion of Ukraine in February 2022, Russian officials have issued numerous nuclear threats (Horovitz et al., 2025). These have arguably increased concerns about nuclear weapon use across the globe – providing Russia with leverage.1 Importantly, fears are not confined to the general public. According to various reports, U.S. intelligence assessed that, had Ukrainian forces succeeded in encircling Russian troops in Kherson in September 2022, there was a roughly 50% likelihood that Russia would have resorted to nuclear use (Woodward, 2024, pp. 117–119). Indeed, such concerns have likely contributed to restraint by Western states in supporting Ukraine, among others slowing down the delivery of advanced weaponries (Horovitz & Wachs, 2022; Stein, 2023; Bell, 2024; Arceneaux, 2023).
Against this backdrop, Russia has also deployed nuclear-capable delivery systems to Belarus. In the summer of 2022, Putin pledged to supply Belarus with delivery vehicles and to provide specialized training to Belarusian forces (The Guardian, 2022). By the summer of 2023, both Putin and Belarusian President Aleksandr Lukashenko, the autocratic leader governing the country since 1994, publicly claimed that the first Russian nuclear weapons had already been transferred to Belarus. Whether or not warheads have followed, however, remains unclear. This move is not without precedent. Throughout the Cold War, the Soviet Union deployed nuclear weapons to six allied countries (Fuhrmann & Sechser, 2013, p. 466). Some allies, such as Poland and the German Democratic Republic (GDR), even maintained their own nuclear-capable delivery systems, while custody of the warheads remained exclusively with the Soviet Union – mirroring NATO arrangements (Nielsen, 1998, p. 65; Pałka, 2018, p. 69).
These developments unfolded against a broader backdrop of geopolitical and domestic shifts beginning in the late 2010s. President Putin had long sought to deepen Belarus’ integration into Russia through the Union State framework. Lukashenko’s turn away from Europe following the contested 2020 election gave this project renewed momentum. This period also encompassed Russia’s December 2021 proposal for a new European security arrangement (Alberque, 2022) and the Western rejection of its demands (Deutsche Welle, 2022), as well as Ukrainian President Volodymyr Zelenskyy’s February 2022 speech, which cautiously suggested that Ukraine might reconsider its nonproliferation commitments in the face of Russian aggression (Zelenskyy, 2022).
The deployments themselves, in turn, were accompanied by doctrinal revisions: In January 2024, Belarus adopted a new military doctrine that emphasized the role of nuclear weapons. In December 2024, Russia published a revised version of its own nuclear doctrine, which explicitly extended a nuclear umbrella to Belarus (Ministry of Foreign Affairs of the Russian Federation, 2024a; Knight & Lau, 2024). In addition, the two countries signed a bilateral security treaty that arguably includes references to the potential use of nuclear weapons (Yeryoma, 2024).
Reports have confirmed the deployment of nuclear-capable missile systems to Belarus and the training of Belarusian military personnel on these platforms (Alberque, 2024, p. 17). To date, Russia appears to have stationed the SS-26 Stone, a ground-launched short-range ballistic missile, as well as the SSC-7 Southpaw, a short-range ground-launched cruise missile, and most recently the intermediate-range ballistic missile Oreshnik on Belarusian territory (Kelly & Osborn, 2023; Sapuppo, 2026). While the presence of nuclear-capable delivery systems has been independently verified, open-source intelligence casts doubt on whether nuclear warheads have been transferred (Kristensen & Korda, 2025). However, recent reports suggest that a potential tactical nuclear warhead storage site within Belarus has undergone significant fortification and modernization (Taranov, 2025). At the same time, Ukrainian intelligence publicly stated in May 2025 that they did not believe any nuclear warheads had been transferred to Belarus to date (Taradiuk, 2025).
While the extent to which nuclear warheads, in contrast to merely nuclear-capable delivery systems, have been deployed to Belarus remains uncertain, the key puzzle concerns the motivation for such deployments. Recent scholarship analyzed the strategic logic behind Russia’s actions, highlighting a range of potential motivations, from arms control considerations to military-driven rationales (Horovitz & Wachs, 2024; Sorg, 2025). These articles have provided important insights into the factual basis of the deployments, their technical details, and the range of potential explanations along with assessments of their likelihood. However, the authors have focused mainly on developing explanations based on conceptual and historical literature, while giving too little attention to existing empirical data and its limitations.
This article approaches the puzzle from a different angle: it seeks to systematically examine the available empirical evidence by employing a congruence analysis case study, which evaluates how well competing theoretical explanations align with observable evidence. Specifically, we compare a comprehensive dataset of official statements regarding the deployments with the expectations derived from existing theories to evaluate the degree of fit between theory and evidence. At the same time, we remain mindful of the limitations of the data.
This article finds substantial evidence supporting the claim that Russia’s deployment of nuclear weapons to Belarus was intended to extend its nuclear deterrent. There are also indications that Moscow aimed to expand its strategic influence, which is especially noteworthy as there are strong incentives against making such rationales public. However, evidence for an assurance-based rationale is minimal. Given the data limitations, the findings presented here should be regarded as preliminary, yet still carrying implications for both scholarly inquiry and policy assessment.
Russia’s behavior in Belarus has important implications for small states in the third nuclear age – ultimately regardless of Moscow’s underlying motivations. These deployments make clear how Washington’s relative retrenchment has enabled competitors to exploit local power asymmetries to advance their own agendas. At the same time, much like the dynamics within the Western alliance system, Russia’s close allies exhibit unequal bargaining power. This speaks to the broader question of the range of options and bargaining levers junior alliance partners possess in the third nuclear age, as laid out in the introduction of this special collection by Braut-Hegghammer and Bowers (2026).
Our findings suggest that the hegemon retains greater agency over nuclear decisions than the protégé: a pattern that may be specific to Russia, or perhaps an overlooked feature of Western alliance structures as well. Indeed, this latter argument has been proposed in existing research (Gheorghe, 2022). Although Belarus is a frontline state and arguably highly vulnerable to nuclear escalation,2 it may be best categorized as a “subordinate” state. An interesting avenue for further research, following the approach of Herzog, Rodriguez, and Sukin (2026) in this special collection, might be to examine how such categorizations apply to authoritarian alliances. Similarly, our analysis differs from that of Liyanage (2026) insofar as Russia holds far greater leverage over Belarus than the United States has ever exercised over its allies. At the same time, given its current geopolitical position, Belarus may be willing to host nuclear weapons without the need for coercion or persuasion. In practice, the relationship may therefore resemble NATO in being largely based on shared interests, even if Russia, in principle, might be more willing than the United States to employ direct coercion.
The article proceeds as follows. First, it offers a literature review of existing scholarship on nuclear weapon deployments more broadly. Second, it outlines the types of data available in the present case, along with their inherent limitations. An appendix ensures transparency and facilitates the replication of our findings. Third, it discusses the observable implications that would be expected if specific motives were at work. Fourth, it systematically examines and categorizes all currently available empirical evidence relating to Russia’s deployment of nuclear weapons to Belarus. Lastly, the article concludes by reflecting on the broader implications of the findings and identifying directions for future research.
Why Do States Deploy Nuclear Weapons Abroad?
The existing scholarship has outlined three motives relating to the deployment of nuclear weapons to foreign states: extended deterrence, assurance and power projection (Fuhrmann & Sechser, 2013).
Extended deterrence” refers to signaling to an adversary that an attack on an ally will be met with force. The central dilemma of nuclear security guarantees lies in making such threats credible in situations where the patron state does not itself face an existential threat (Schelling, 1966). States can attempt to address this through costly signaling (Fearon, 1997; Quek, 2021), and nuclear deployments are among the most powerful signals available. They involve upfront sunk costs, and they function as a form of hand-tying: the presence of the patron’s forces creates a tripwire effect, making escalation automatic if those forces come under attack. Such deployments also carry an inherent risk of losing control over the weapons themselves – no matter how robust the safeguards, the host state retains a geographic advantage that could enable it to seize them in a crisis.
The role of nuclear deployments as instruments of extended deterrence has shifted historically. For instance, while NATO emphasized their deterrent value during the mid-Cold War, extended deterrence became less central between 1990 and 2015. The evolution can be traced through the development of NATO’s strategic concepts. In the late 1940s, the United States regarded nuclear weapons as purely strategic weapons, as evidenced by military planning documents NSC-30 (United States) and DC 6/1 (NATO) (Heuser, 1995, pp. 41–42; Sagan, 1989, pp. 15–16). Thus, there was no incentive for the widespread deployment of tactical nuclear weapons. However, with the evolution of NATO’s doctrine from MC 14/2 and MC 70 to MC 14/3, a more flexible posture, and the deployment of nuclear weapons around the world, emerged (Heuser, 1997, pp. 43–47; Wenger, 2006, pp. 170–176; Gavin, 2012, p. 34). It was believed that such weaponry might deter a Soviet attack as it simultaneously enhanced warfighting capabilities, potentially stopping a conventional intrusion, and enhanced the risk for nuclear escalation.
On the other side of the Iron Curtain, nuclear weapons were conceptualized differently. In the early Cold War, the Soviet Union based its planning on two principles: first, nuclear war could not be contained and would ultimately escalate; second, and consequently, the socialist countries were obliged to preemptively use their nuclear weapons were the West about to attack (Heuser, 1993, p. 438; Nielsen, 1998; Uhl, 2006, pp. 58–62). By the late 1960s, Soviet strategy shifted from preemption toward a survivable second-strike capability (Nielsen, 1998, p. 70). At both phases, however, the dissemination of nuclear weapons to allies, particularly within the Warsaw Pact, was seen as necessary to provide deterrence and defense.
The second motive is assurance, which rests on the idea that credible security guarantees can strengthen the relationship between the protector and the protégé. Importantly, the signal-receiving actor of interest here is the ally, not the adversary. Indeed, the adversary and ally may interpret these signals quite differently, highlighting the importance of distinguishing between what assures, what deters, and under what conditions one complements the other. The scholarly literature has predominantly emphasized nonproliferation as a goal of assurance. However, in reality, protecting states can pursue broader political, economic, or security objectives in their relationships with protégés (Fuhrmann & Sechser, 2013; Sorg, 2024). Unlike extended deterrence, where the primary audience is the adversary, the main recipient of the signal in this case is the ally. The protected state must believe that the security guarantees are strong and reliable enough to align its policies with the protecting state’s interests: for instance, to forego developing its own nuclear weapons.
The United States has relied considerably on nuclear-backed security guarantees to inspire a sense of security among allies (Lanoszka, 2018a). Moreover, it has been argued that even in the autocratic alliances of the Warsaw Pact, nuclear security guarantees played a noteworthy role (Lanoszka, 2018b). However, the most thoroughly researched historical evidence on using nuclear weapons to assure allies remains the United States. For example, U.S. deployments to Taiwan were kept secret from potential adversaries. Thus, deterrence was likely not the main goal. Instead, the purpose seems to have been assurance or power projection (Burr, 2006). In Europe, “NATO leaders had come to see [foreign deployed nuclear weapons] as a symbol of the American commitment to defend Europe” (Bird, 2008, p. 67). Among others, this pertained to atomic demolition munitions, for which NATO never found a convincing military rationale, and Honest John surface-to-surface rockets deployed in Greece and Turkey until the late 1980s: despite being practically unusable according to U.S. Department of Defense planners, U.S. officials thought that a withdrawal would diminish the political commitment that they symbolized (Arkin & Fieldhouse, 1985, p. 109). These are just two of several historical examples in which U.S. nuclear weapon deployments appear to have been driven less by military necessity than by the goal of providing assurance, showcasing how the concept is related but distinct from extended deterrence.
The final motive is power projection. Here, a state exploits the geographic or strategic advantages created by nuclear weapon deployments to enhance its capacity to threaten or coerce an adversary. While the signal receiver of interest is the adversary, power projection can be distinguished from extended deterrence as it creates immediate and direct, rather than indirect, benefits for the deploying state: that is, the signal is not intended to protect allies, but to directly increase the deployer’s leverage over an adversary. Extended deterrence, for example, can advance the patron’s broader strategic interests, but the benefits are mediated through alliance politics. Power projection, by contrast, provides the guardian with a direct operational advantage.
For instance, historians argue that influential U.S. decision-makers in the Cold War viewed the flexible response doctrine and the associated nuclear deployments as a means to geographically contain potential conflict within Europe (Heuser, 1995, p. 58). Indeed, many allies feared that the United States would willingly accept the devastation of the European battlefield to protect itself (Howard, 1982/83, p. 318). Other examples include deployments to countries without intentions to protect them, as when the United Kingdom deployed nuclear weapons to Cyprus. These deployments were primarily aimed at strengthening British alliances in the Middle East, supporting potential limited war scenarios against Egypt, or contributing to planning for a large-scale war against the Soviet Union; none of these related to the defense of Cyprus (Moore, 2001, pp. 62–63). Power projection might also explain certain deployments by the United States to Asian countries. The U.S. 8th Tactical Fighter Wing at Kunsan, South Korea, the 18th Tactical Fighter Wing at Kadena Air Base in Okinawa, Japan, and the 3rd Tactical Fighter Wing at Clark Air Base in the Philippines formed part of a three-base strike force for targets in China in the 1970s (Kristensen & Norris, 2017, p. 351). The United States believed itself responding defensively to the threat of a nuclear-armed China (Trachtenberg, 1999, pp. 385–389). But for the host states, especially South Korea and the Philippines, China was then no significant threat at all.
Admittedly, there are several additional motives that could account for the deployment of nuclear weapons to Belarus. One especially prominent one is that Russia might eventually use them as bargaining chips in future arms control negotiations. NATO has long sought to link reductions in its own tactical nuclear weapons – particularly those deployed in Europe under nuclear sharing arrangements – to reductions in Russia’s much larger non-strategic arsenal. Russia could use the deployments to Belarus to offset such demands and accept smaller overall reductions. Indeed, this appears quite likely and has been proposed by existing research as a potential explanation (Horovitz & Wachs, 2024; Sorg, 2025).
Whether this mechanism is in fact at work, however, will only become clear over time. Our analysis therefore focuses on motives for which we expect to find observable evidence in the data that we could collect and analyze today. From current public statements alone, it is nearly impossible to infer whether Russia will use the deployments as a bargaining chip in the next round of arms control talks. Thus, although other explanations remain possible, the methodology and data we employ are best suited to testing the three fundamental motives outlined above.
Historical Precedent
In addition to theoretical approaches, historical experience may provide a useful lens for understanding the current deployment. The Soviet Union had deployed nuclear weapons to six countries throughout the Cold War: Cuba, Czechoslovakia, East Germany, Hungary, Mongolia, and Poland (Fuhrmann & Sechser, 2013, p. 466). Early Soviet nuclear strategy rested on two assumptions. First, victory required preemptive destruction of enemy nuclear forces, and, second, nuclear war would inevitably escalate into an all-out exchange (Heuser, 1993, p. 438). This produced plans for preemptive counterforce strikes against both strategic and tactical targets, with nuclear dissemination to Warsaw Pact allies regarded as additional firepower in an all-out exchange (Nielsen, 1998, p. 65; Pałka, 2018, p. 69).
Just as in the case of NATO, Warsaw Pact allies oscillated between regarding nuclear weapons as a tool of assurance for their own security and viewing them as dangerous weapons that would most likely be used on their own territory (e.g., Mastny, 2001, p. 24, 29). Nuclear warheads remained under the control of Soviet forces during peacetime, although some were designated for use by delivery vehicles owned by the host states. For instance, during the 1960s and 1970s, Soviet personnel would have provided nuclear warheads to missiles belonging to the GDR in times of war. In Poland, the military possessed nuclear-capable missiles that could be launched from Polish MiG-21 and Su-7 aircraft (Pałka, 2018, p. 69). This seems to mirror today’s arrangement with Belarus. Although the transfer of nuclear warheads remains uncertain, it is evident that Belarusian forces possess nuclear-capable delivery systems and have received training to operate them.
By the late 1960s, the strategic alignment of the Soviet Union shifted from preemption to securing a survivable second-strike capability, supported by improved monitoring, mobile weapons, and a conceptual distinction between tactical and strategic arms (Holloway, 2020, pp. 79–82; Nielsen, 1998, p. 70; Heuser, 1993, pp. 438–41). This evolution deepened Warsaw Pact integration, as new consultative mechanisms institutionalized allied involvement (Gheorghe, 2022, p. 105). Some scholars argue that participation, assurance and general intra-alliance politics were an important part of Soviet nuclear policy (Lanoszka, 2018b). However, the degree of control over nuclear weapons by allies remains debated (Kramer, 1993, p. 8).
In some cases, nuclear warheads even remained stored on Soviet territory and were to be transferred to allied states only if needed. For example, Bulgarian forces were prepared to receive warheads from a Soviet assembly brigade and then transport them by helicopter to their missile systems (Saychuk, 2020). This might potentially serve as a blueprint for current deployments, assuming Russia will stop short of transferring warheads to Belarus. However, warhead deployments to allied nations increased markedly in the mid-1960s, when the Soviet Union engaged in a number of wargaming exercises that stressed the importance of forward deployed nuclear weapons (Becz et al., 2019, pp. 100–101).
Control over warheads rested with the Soviet military, which maintained a centralized command structure for both domestic and foreign-deployed nuclear arms (Nielsen, 1998, p. 133). Since the Soviet period, the 12th Main Directorate (12th GUMO) has managed nuclear armaments, including forward-deployed weapons, and continues to perform this role in Russia today (Becz et al., 2019, p. 43). Historical precedent therefore suggests a similar arrangement is likely in Belarus, as official statements have also indicated (Jones, 2023).
It is also important to briefly situate the nuclear deployments to Belarus within the most recent historical context. Relations between Russia and the West have deteriorated over the past decade, and Minsk has become increasingly dependent on Moscow. Following Russia’s annexation of Crimea and its support for separatist forces in eastern Ukraine, financial sanctions and diplomatic restrictions were imposed (Ashford, 2016). As tensions continued to escalate, Russia proposed a sweeping revision of the European security order through two draft treaties. Building on initiatives from the late 2010s, the treaties sought to restrict NATO’s membership policies and military deployments in Europe (Ministry of Foreign Affairs of the Russian Nation, 2021). While Western governments signaled willingness to negotiate, neither the United States nor NATO were prepared to accept these Russian demands. Simultaneously, President Zelenskyy hinted that, if faced with Russian aggression, Ukraine might consider the Budapest Memorandum no longer binding (Zelenskyy, 2022).
The situation in Belarus further shaped the broader context. Following the 2020–2021 mass protests, Lukashenko aligned more closely than ever with Moscow and increasingly viewed Russia as his main security guarantor. Fears among Belarusian elites of Western-backed opposition, reinforced by severe EU and U.S. sanctions, likely deepened this dependence (Miadzvetskaya, 2022). Some scholars therefore argue that Belarusian domestic insecurity and Russian strategic interests jointly motivated the nuclear deployments (Horovitz & Wachs, 2024; Sorg, 2025). We take a different approach, focusing primarily on public statements while remaining mindful of this broader context.
Methods, Data and Limitations
As our goal is to systematically compare existing data against various theoretical frameworks, squarely focusing on the empirical evidence, congruence analysis emerges as the most suitable methodological approach. This method enables researchers to assess the explanatory power of theoretical propositions by comparing their empirical expectations with observed patterns. It evaluates the degree of fit between theory and evidence, allowing scholars to judge the plausibility of a given explanation. More importantly, congruence analysis can aid in narrowing down alternative motives by identifying empirical findings inconsistent with the expectations generated by competing mechanisms.
In an ideal research environment, scholars would have access to detailed archival evidence revealing how decisions were made and which considerations mattered most. They could also use memoirs, original interviews, and declassified intelligence from other states. Although each source has limitations, together they would allow for a careful reconstruction of the case. Unfortunately, none of these sources are available in our case. Three constraints dominate. First, the deployments constitute an ongoing development, with facts continuing to change; second, both Russia and Belarus are authoritarian regimes which lack transparency; third, even in democratic systems, nuclear weapons policy remains subject to strict secrecy, limiting data availability. Hence, even Western information releases are extremely patchy (Fraise, 2024).
Thus, researchers are left with fragmented and heavily skewed empirical evidence. This includes official statements from Russian and Belarusian authorities, likely framed under considerations of strategic messaging; commentary from domestic media and bloggers operating under severe constraints on press freedom; open-source intelligence, which can shed light on the “what” but rarely on the “why”; and Western media reports citing intelligence assessments, which while helpful are also shaped by strategic considerations. In addition, our data points are not independent observations. In most cases, statements represent reactions to earlier statements or actions, evolving across time. Sometimes they might even be orchestrated: that is, Russian officials could potentially fulfill specific roles within a broader communication strategy, as some believe is the case with Dmitry Medvedev, Deputy Chairman of the Security Council of the Russian Federation. While we are mindful of these challenges, we believe that congruence analysis is well suited to address many of them.
At the same time, it is important to underscore the inherent limitations of our methodological approach. Unlike process tracing, which aims to uncover causal mechanisms and typically relies on extensive empirical evidence, congruence analysis cannot establish causality. It can only evaluate whether empirical patterns are consistent with the expectations derived from a particular theory. Crucially, such consistency does not rule out the possibility that the observed patterns may be the result of entirely different causal mechanisms. At best, congruence analysis allows researchers to argue that, based on available evidence, a given theoretical explanation appears more plausible – or less likely to be incorrect – than its alternatives.
What Should We Be Looking For?
The models outlined above enable the derivation of observable empirical implications that can serve as indicators for evaluating the plausibility of each theoretical explanation (for a summary, see Table 1). Ideally, such implications are both specific, being uniquely predicted by a single theory, and discriminatory, meaning their presence would significantly weaken or rule out alternative explanations. In practice, however, the non-uniqueness of predictions, the complexity of the case under study, and the limited availability of high-quality data often constrain the ability to derive truly exclusionary implications.
Table 1
Alternative Theories and Predicted Empirical Evidence.
| MOTIVES | EMPIRICAL INDICATORS |
|---|---|
| Extended deterrence Russia deploys nuclear weapons to deter adversaries and protect Belarus | Official framing: Russian and Belarusian statements present the deployment as deterring NATO/Western action and protecting Belarus. |
| Military indicators: doctrinal, command-and-control, or posture changes consistent with limited nuclear warfighting. | |
| Credibility costs: evidence of diplomatic and strategic costs, sunk costs, or reduced reversibility that increase commitment credibility. | |
| Assurance Russia deploys nuclear weapons primarily to assure Belarus and strengthen alliance confidence | Official framing: Russian statements depict the deployment as reassuring Belarus and signaling alliance reliability; Belarusian statements portray it as stabilizing. |
| Alliance entanglement: deeper Russian involvement in Belarus’s defense that raises the costs of aggression and signals protection. | |
| Power projection Russia deploys nuclear weapons to increase its own strategic reach vis-à-vis the West | Official framing: Russian rhetoric emphasizes strategic reach. |
| Operational indicators: force posture consistent with forward coercive capability and escalation leverage. | |
| Belarusian alignment: Belarusian rhetoric endorses or echoes claims about expanded Russian leverage. |
If the deployment of Russian nuclear weapons to Belarus is primarily intended as an act of extended deterrence, several empirical indicators should be observable. First, official Russian statements should explicitly frame the deployment as a means of deterring Western intervention, particularly on the part of NATO, emphasizing its role in extending Russia’s nuclear umbrella to Belarus. Second, corresponding Belarusian rhetoric should affirm this interpretation, portraying the deployment as a strategic shield against external threats. Third, one would expect to observe Russian military behavior consistent with a strategy of limited nuclear warfighting, signaling an ability to prevail in a confined nuclear exchange, thereby reinforcing deterrence. This might include doctrinal changes, command-and-control integration, or force posture adjustments. Finally, Russia should demonstrate a willingness to incur tangible financial, diplomatic, or strategic costs as sunk costs that serve to enhance the credibility of its commitment to defend Belarus. In this vein, evidence that Russia is deliberately limiting its ability to withdraw nuclear weapons or delivery systems from Belarus on short notice would lend additional support to this explanation.
Conversely, if the primary function of the deployment is to provide assurance to Belarus, particularly to bolster Minsk’s confidence in Russia’s security commitment, a different set of empirical expectations follows. First, Russian leadership should articulate the deployments as assurance measures designed to signal steadfast alliance support and to calm elite-level fears in Belarus about abandonment. Second, Belarusian officials, in turn, should echo this interpretation, emphasizing the deployments as stabilizing rather than escalatory. Third, Russia should adopt measures that increase the likelihood that any military attack on Belarus – especially one involving nuclear facilities or infrastructure – would inevitably draw in Russian forces, thus raising the cost of aggression and signaling protection. This might involve integrating Belarus more deeply into Russian command-and-control structures or stationing Russian personnel alongside the weapons. While such observable behavior may also be consistent with the extended deterrence explanation, it arguably provides somewhat stronger support for the assurance-based interpretation.
Finally, if the deployment reflects a motive of power projection, other implications should be apparent. First, Russian official rhetoric should frame the nuclear deployment in terms that emphasize strategic reach, regional dominance, or coercive leverage. This might go as far as suggesting that forward-deployed nuclear weapons provide operational flexibility or greater pressure on the West. Second, Belarusian discourse, while more constrained, may nonetheless acknowledge or endorse the notion that the deployments serve to expand Moscow’s strategic influence or bargaining power. Third, beyond discourse, observable Russian behavior would be geared toward increasing its capacity to conduct or threaten offensive operations. For instance: integrated nuclear-conventional exercises that simulate first-use scenarios or rapid escalation capabilities, or forward deployment of supporting assets (e.g., delivery systems or logistical infrastructure) that facilitate force projection.
There are important caveats to the type of indicators we can expect to see in our data. First, Moscow and Minsk are likely to have incentives to obscure an assurance rationale. Public displays of assurance played a prominent role in Western alliance politics, particularly during the most intense phases of the Cold War. However, in the context of the asymmetrical and politically sensitive relationship between Belarus and Russia, leaders on both sides may be reluctant to signal overtly that Minsk is overly dependent on Moscow. For Lukashenko, it undermines his domestic legitimacy; for Putin, it could complicate his support for a protégé whose authority rests, at least in part, on the appearance of sovereign agency. More generally, between autocratic regimes, public displays of assurances appear to be less necessary, and by the very nature of our data, we will not be able to uncover private ones.
Second, it seems important to note that the cogs and wheels underpinning the power projection causal mechanism might also be difficult to observe. On the one hand, Russian elites do seek to project strength to their own population. However, both domestic and international incentives encourage the downplaying of power projection motives. Consequently, the available evidence is inherently biased against confirming this motive. In short, we are aware that our data are non-ideal and that they favor some theories over others. Precisely for this reason, it will be particularly noteworthy if we find evidence for motives that the data are biased against. Moreover, this complements existing approaches, which have focused less on the implications of public statements, but rather emphasized the construction of plausible arguments given the geopolitical context (Horovitz & Wachs, 2024; Sorg, 2025).
Empirical Analysis
In this section, we systematically evaluate a comprehensive set of data points related to Russia’s deployment of nuclear weapons to Belarus and compare them with the empirical patterns we expect under extended deterrence, assurance, and power projection. The data used in this analysis derives from a long-term collection project (Horovitz et al., 2025). This chronology of Russian nuclear narratives, Western responses, and potential escalation pathways in the context of Russia’s full-scale invasion of Ukraine aims to document all relevant events and statements from autumn 2021 (the months preceding Russia’s full-scale invasion of Ukraine) to January 2025 (the end of the Biden administration). Compiled by a multilingual research team, the project sought to comprehensively identify all available data points from open sources. Despite extensive efforts over hundreds of hours, we cannot fully rule out the possibility that some entries were missed.
From this chronology, we extracted the 57 relevant data points, spanning from November 2021 to December 2024, that may offer insight into Russian intentions vis-à-vis Belarus. A full list of these observations is provided in the Appendix. This appendix discloses our full data sources and coding decisions, allowing readers to assess our claims. In doing so, we aim to enhance the study’s transparency, and to enable others to critically engage with our findings on clearly defined methodological grounds. In the following section, we evaluate this material.
Extended Deterrence
There are multiple statements since the first mention of potential Russian nuclear deployments to Belarus in 2021 that support the extended deterrence explanation. Numerous statements frame the deployments as a means to deter NATO states from interfering in Belarus. The deployments have also entailed reputational costs for Russia, prompting criticism from Western governments and, at times, even from China.
First, Russian officials have frequently emphasized that the deployments are intended to deter attacks from NATO countries on Belarus. This mirrors Soviet planning, where nuclear deployments were presented as essential military instruments to counter potential NATO aggression against Communist states. For instance, in summer 2023, President Putin stated during a meeting of the Russian Security Council that an attack on Belarus would be treated as an attack on Russia and met with an appropriate response – likely implying nuclear retaliation (President of Russia, 2023). This marked an early articulation of what would later become part of Russia’s revised nuclear doctrine: in September 2024, Putin announced live on television that Belarus would be granted equivalent nuclear protection under Russia’s nuclear umbrella (President of Russia, 2024a). A few months later, he reiterated that the defense of Belarus was a central element of the revised doctrine (Tass, 2024a). Deputy Security Council Chairman Dmitry Medvedev further emphasized this line of reasoning. He repeatedly stated that an attack on Belarus could legitimize the use of nuclear weapons by Minsk (Medvedev, 2024). The full doctrine, explicitly mentioning the use of nuclear weapons in defense of Belarus, was eventually released in December 2024 (Ministry of Foreign Affairs of the Russian Federation, 2024a). Lastly, during joint military exercises with Belarus, which entailed a nuclear component, Putin again claimed that the security of Belarus was treated as equivalent to that of Russia (Belta, 2024a). This claim was repeated by Foreign Ministry Spokeswoman Maria Zakharova, who stated that the deployments were intended to protect Belarus (Ministry of Foreign Affairs of the Russian Federation, 2024b; Ministry of Foreign Affairs of the Russian Federation, 2024c).
Second, these Russian statements have been reinforced by officials from Belarus. In March 2023, Putin told a journalist that nuclear warheads would be deployed to Belarus by the summer. Following this announcement, Belarus’s foreign ministry justified the decision by pointing to alleged NATO aggression and framed the deployments as a way to “strengthen its own security and defense capability” (Osborn, 2023a). In an annual address to parliament around the same time, Lukashenko emphasized similar sentiments. In the face of a potential invasion, nuclear weapons were necessary to protect the sovereignty and independence of Belarus. He even implied Belarusian control over them (Davis, 2023). Belarusian UN Ambassador Valentin Rybakov reiterated that the deployments were a reaction to NATO threats (Lederer, 2023). After announcing that Belarus had begun receiving Russian nuclear warheads and missiles in June 2023, Lukashenko further asserted his willingness to use them to defend national territory and repel foreign attacks (Eruygur, 2023).
In July of the same year, Lukashenko continued to emphasize the deterrence narrative. He stated that the weapons would not be used without his approval and that they were a form of protection against possible aggression (Euractiv, 2023). A few weeks later, he warned that any attack by Poland, Lithuania, or Latvia would be met with full force (President of the Republic of Belarus, 2023). In addition, while backtracking on claims that he had control over these weapons (Davis, 2023), in two separate statements in fall 2024, Lukashenko continued to stress their role in protecting the country. He declared that he would do everything in his power to ensure their use in case of an attack. He also alleged that the deployments had already helped deter NATO aggression (Belta, 2024b; Rosenberg, 2024; Radio Free Europe, 2024). However, it should be noted that we cannot determine whether Belarus’s reaffirmation of Russian statements reflects genuine agreement, is meant to please decision makers in Moscow, or results from outright coercion.
There have also been a series of statements by officials from both countries which point to the protection of Belarus alongside the protection of Russia. During a joint press conference in June 2022, Lukashenko welcomed the deployments, citing alleged Western threats to both states (President of Russia, 2022a). Furthermore, in a joint statement, defense ministers of Russia and Belarus claimed that the deployments could protect both Russia and Belarus (Karmanau, 2023; Lowe et al., 2023). In addition, Kremlin spokesperson Dmitry Peskov reasoned that the sovereignty of the Union State of Russia and Belarus was being upheld by ensuring the operational readiness of tactical nuclear weapons (Tass 2024b).
As noted above, a willingness to incur costs can serve as an additional indicator of a deterrent logic, and there are observable diplomatic costs. Many European and NATO officials condemned the deployments as escalatory and threatening, with some governments arguing that they had worsened the regional security environment (e.g., Hajjaji & Clinton 2023; Peleschuk, 2023; Government of Poland, 2023). After Lukashenko explicitly cited the hostile relationship with the Baltic states and Poland as a rationale for the deployments (President of the Republic of Belarus, 2023), officials from these countries declared the deployments as direct threats against their countries (President of the Republic of Lithuania, 2023).
Such criticism highlights that the deployments are costly for Russia. However, within the broader context of the current relationship between Russia and the West, their impact might be rather limited. Since the start of its full-scale war against Ukraine, Russia has already suffered major diplomatic and economic consequences. One noteworthy deviation from this pattern is a statement by the Chinese ambassador to the UN Geng Shuang, who expressed opposition to any nuclear deployments during a UN session specifically addressing Russia’s actions in Belarus (Davis, 2023). Such criticism is notable, given China’s reluctance to condemn Russia’s invasion of Ukraine and its broader alignment with Moscow. It stands out as one of the few public instances – alongside warnings against nuclear use in Ukraine – in which Beijing openly signaled disagreement with Russia. Chinese criticism should therefore be considered separately from Western objections.
Lastly, we assess whether military activity related to the deployments supports a limited nuclear warfighting strategy, which could further strengthen the extended deterrence narrative. While the revised doctrine may be read in this way, it does not lower the threshold for nuclear use. The criteria for employment remain unchanged, but they are now extended to Belarus. However, Belarus and Russia also conducted joint military exercises that entailed nuclear weapon-related activities. Most recently, these drills included simulations of preparing a nuclear strike using an Oreshnik missile (Moscow Times, 2025). Nevertheless, it remains unclear from the exercise under what circumstances such a nuclear employment might actually take place.
Assurance
In contrast to the deterrence rationale, we could identify much less evidence underlining the assurance interpretation. This comes even though scholars have highlighted this motive in Soviet nuclear policy (Lanoszka, 2018b). Indeed, neither the Russian nor the Belarusian leadership has put emphasis on these deployments as strengthening their alliance. If anything, certain statements have highlighted the importance of the Union State arrangement, under which, since 1999, both countries have aligned some of their institutional frameworks and policies (Deen et al., 2021). As noted above, Kremlin spokesperson Dmitry Peskov framed joint military exercises as a means of upholding the sovereignty of the Union State (Tass, 2024a). Beyond official statements, the need for Russia to staff deployment sites with its own military personnel, as peacetime control remains with Russia, means that the deployments inevitably draw its forces into a conflict if Belarus is attacked. Along these lines, joint military exercises and Lukashenko’s announcement of inspections of nuclear delivery systems may suggest growing integration of command-and-control structures (AFP, 2024). Both could be interpreted as primarily being aimed at assurance. At the same time, such integration might be simply unavoidable. It is also worth mentioning that Lukashenko suggested that other countries joining the Belarus-Russia union could also host nuclear weapons – indicating potential assurance motives (Kelly, 2023). Yet many of these interpretations remain rather speculative claims. Thus, we find few clear instances where the assurance motive aligns with our empirical data.
Power Projection
Finally, a substantial number of data points align with our power projection criteria. That is, these statements frame the deployments as mainly benefiting Russia, highlighting topics of strategic reach, great power competition or coercive leverage. This may coincide with Belarus exercising relatively little actual control over these weapons, a dynamic also noted in studies of Soviet deployments, where the appearance of allied inclusion often diverged from the actual practice (Kramer, 1993, p. 8). Russian officials have emphasized such rationales repeatedly. For instance, shortly after the agreement to host nuclear weapons in Belarus was signed in May 2023, Putin stressed that the deployments were intended to protect Russia from strategic defeat, which placed Russian interests at the forefront (Osborn, 2023b). Furthermore, during joint military exercises in 2024, Russian Foreign Minister Sergey Lavrov said he hoped the deployments would remind the West of the stakes involved, particularly amid plans to supply F-16 jets to Ukraine (Sputnik, 2024). These comments suggest that the deployments are part of Russia’s broader strategy of nuclear intimidation.
Officials in Belarus also offered statements that would align with such reading. In fact, the first time the plan was announced, Lukashenko framed the deployments as allowing Russia to react to NATO provocations (Isachenkov, 2021). This is remarkable, as it implies that Belarus’s own strategic interests are not the primary consideration in the deployments. Between December 2021 and February 2022, Belarus first presented and subsequently implemented an amendment to its constitution overturning a constitutional obligation to remain “nuclear-free and neutral”, so permitting nuclear deployments. Officials offered limited justification, but they referred to a potential NATO threat, aligning with extended deterrence logics, as well as framing the deployment as an offer to Russia (Tass, 2024c, Williams & Williams, 2022). Moreover, Lukashenko has publicly linked the stationing of these weapons to becoming a target for Western forces (Tass, 2024c). While not direct evidence for power projection, such reasoning at least implies that officials in Belarus are aware of the negative externalities that Minsk might suffer.
Officials from both countries have also often highlighted that these deployments would merely mirror NATO arrangements. This might be a justification, rather than revealing a strategic logic – but it could also mean that Russia sees the deployments as a tool in its competition with the United States, in contrast to them being a means to protect Belarus. In December 2022, Putin framed the deployments as analogous to long-standing U.S. nuclear sharing practices (President of Russia, 2022b). In March 2023, he told a journalist that nuclear warheads would be deployed to Belarus by the summer, with a storage facility to be completed by July 1 and ten Belarusian aircraft already certified for nuclear use – referring to U.S. nuclear sharing practices to legitimize the new developments, and using the same argument when a formal agreement was signed in May 2023 (Troianovski et al., 2023; Faulconbridge, 2023). Moreover, both Putin and Lukashenko together questioned the significance of the deployments by arguing that NATO engaged in similar practices (President of Russia, 2024b). In addition, in a July 2023 interview, Russian Deputy Foreign Minister Sergei Ryabkov argued that criticism of the deployments was unfounded given longstanding U.S. deployments in Europe, adding that growing threats against Russia required an appropriate military-technical response (Popov, 2023). This further suggests that at least part of the rationale for the deployments is to poke at NATO and to protect Russia, not necessarily Belarus.
Lastly, as we noted above, most foreign observers have largely blamed and criticized Russia, not Belarus, for these deployments. This provides some evidence for the extended deterrence narrative, as the Russian government incurs costs for its actions. However, it could also mean that most Western governments regard them foremost as a tool employed by Russia against the West. However, the focus on Russia might also derive from the fact that in the broader strategic picture, it is the Kremlin, not Minsk, that poses the principal threat to regional security.
Conclusion
This article analyzed the existing empirical evidence regarding Russia’s deployment of nuclear delivery vehicles, and potential deployment of nuclear warheads, to Belarus. Specifically, it assessed how a comprehensive list of data points aligns with three theoretical explanations for nuclear weapon deployments: extended deterrence, assurance and power projection. Throughout, the analysis remained mindful of the significant limitations imposed by the nature of the available evidence. However, congruence analysis can address data limitations by assessing the degree of fit between theoretical expectations and observable patterns. While it cannot establish causal relationships, it enables researchers to evaluate the relative plausibility of competing explanations.
Each of the tested theoretical models generates distinct expectations. If the deployment serves extended deterrence, we should observe Russian and Belarusian rhetoric framing it as a protection against NATO, military preparations that increase the possibility for limited nuclear use, and Russia incurring financial or diplomatic costs. An assurance-based explanation implies emphasis on alliance solidarity, and measures that entangle Russia in Belarus’s defense. A power projection logic suggests rhetoric highlighting strategic reach or coercion, Belarusian acceptance of an expanded Russian role, and preparations for offensive nuclear use. These divergent expectations provide a basis for evaluating which motive is more plausible considering the available evidence.
Our findings indicate that there is considerable empirical support for the view that Russia’s nuclear deployment to Belarus was primarily motivated by extended deterrence. While some evidence also points to an ambition to bolster Moscow’s strategic reach, there is little to suggest that the move was intended to assure Belarus. At the same time, our analysis underscores the limitations of the existing data, which restrict the certainty of any claims. Nevertheless, these conclusions carry important implications for both policy formulation and academic debate.
First, with respect to policy implications, Russia’s actions in Belarus clearly signal a growing willingness on Moscow’s part to engage in nuclear risk-taking. This development should prompt NATO to adjust its threat assessments accordingly and reinforce its defensive posture. However, the ambiguity surrounding Russia’s underlying motivations complicates Western planning. If the deployment is primarily driven by a desire to project power, it would represent the most destabilizing scenario. A rationale based on extended deterrence would be somewhat less concerning. An assurance-based motive would be the least problematic. Should relations improve and arms control become feasible again, these deployments might eventually serve as bargaining chips. In that case, NATO might treat them as an entry point for negotiations, while establishing easily reversible infrastructure upfront that can then be traded away.
Second, from a scholarly perspective, the intersection of nuclear weapons and alliance dynamics has long been a focal point in international relations research. Yet, Russia’s handling of the nuclear aspects of its partnerships – both past and present – remains insufficiently explored. This study highlights the considerable challenges researchers face. These limitations underscore the need for further theoretical and historical inquiry, which may help bridge some of the existing empirical gaps. Given the increasing assertiveness of Russian policy in Europe, addressing these academic blind spots has become essential for understanding contemporary security developments.
Additional File
The additional file for this article can be found as follows:
Data Appendix
The Appendix provides a comprehensive chronology of events and statements from November 2021 to December 2024 concerning Russian and Belarusian narratives, as well as Western responses, related to Russia’s deployment of nuclear weapons to Belarus. DOI: https://doi.org/10.31374/sjms.497.s1
Notes
[1] To illustrate: the Munich Security Index has tracked public risk perceptions across 11 countries since 2021. Compared to the first year the survey was run, the average perceived risk of “nuclear weapon use by an aggressor” has increased in every country (Munich Security Conference, n.d.).
[2] For instance, in a U.S. wargaming exercise conducted during the Obama administration, senior officials decided to launch a nuclear strike against Belarus in response to Russian nuclear use, although Belarus was not part of the simulated conflict (Kaplan, 2020).
Acknowledgements
We would like to thank the editors of this special collection, Målfrid Braut-Hegghammer and Ian Bowers, both for including us in this project and offering numerous pertinent suggestions. We are also grateful to the other contributors to this special collection for the valuable feedback we received during our various joint meetings. Finally, we would like to thank the editors of the journal and the anonymous reviewers for their thoughtful comments, which greatly improved this article.