Russia’s Nuclear Signalling Problem: Too Much Left to Chance?

Since the beginning of the war in Ukraine, Russian officials have issued a steady stream of nuclear threats—some explicit, some insinuated, and almost all difficult to interpret. Early in the conflict, these signals still seemed to constrain policy responses in Europe and the United States. Debates over air defence systems, long-range weapons, and other forms of deeper western involvement were arguably impacted by fear of escalation.

Yet, as the war has dragged on, that fear appears to have diminished. Western states have gradually expanded military support to Ukraine despite repeated Russian warnings, and actions once considered escalatory have become routine. Have Russian nuclear threats stopped working altogether? And what does Moscow’s signalling game over the past four years suggest about its nuclear calculus today?

The basic logic behind nuclear brinkmanship is not new. As Thomas Schelling famously argued, nuclear threats gain credibility when leaders “leave something to chance”—that is, when they create a risk that events may spiral out of control. In doing so, threats that would otherwise lack credibility—because of secure second-strike capabilities—are endowed with a degree of plausibility. By introducing the possibility of uncontrolled escalation, states seek to exploit their adversaries’ fear and risk aversion, shifting the burden of de-escalation onto them. Much of the theoretical literature building on Schelling has sidelined ‘chance’ as something external to political control: the result of accidents, misperception, or organisational failures. In this view, escalation risks emerge despite leaders’ intentions, not because of them.

In my ongoing research project, I investigate a different interpretation. States do not merely react to uncertainty but harness it. I study how ambiguous nuclear threats—messages that are vague, inconsistent, noncommittal, or internally contradictory—produce coercive effects, and attempt to identify concrete mechanisms states use to introduce or amplify ambiguity. The goal of leaving something to chance is not to make nuclear use seem likely, but to make it impossible to rule out. Russia’s behaviour since February 2022 provides a pertinent illustration of this strategy.

Ambiguity in Practice: Russia’s Early War Signalling

One of the earliest signals came on 27 February 2022, when Vladimir Putin ordered Russian nuclear forces to a ‘special regime of combat duty’. The announcement was highly visible but operationally opaque. It did not correspond to established Russian nuclear doctrine or what is known about its nuclear strategy, nor did it clarify what had changed in practice. No explicit threat was issued, no red line drawn. Yet the signal was effective precisely because of its ambiguity: it raised the perceived risk of escalation without committing Russia to any specific course of action if western states failed to comply.

This pattern has been recurring throughout the conflict. Russian officials have invoked catastrophic but undefined scenarios—warning of “consequences never seen in your history”—without specifying triggers or thresholds. Such language allows different audiences to interpret the signal in different ways. Domestic audiences may read it as a demonstration of strength and resolve. To members of the public in western states, who are not immersed in intelligence briefs about actual changes in Russian nuclear posture, this may seem like a credible warning of nuclear escalation. Policymakers, facing these conflicting interpretations and domestic pressure, tend to err on the side of caution.

Interpretation of nuclear doctrine and Russian strategy is complicated by the distinctly symbolic and ideological character of its security discourse.

At the same time, Russian signalling has not been confined to rhetoric. Physical actions have reinforced the sense that escalation risks may not be fully controllable. Russian aircraft have repeatedly conducted unsafe intercepts and ‘buzzing’ manoeuvres near NATO forces. Military operations around nuclear facilities—most notably intense combat around the Zaporizhzhia nuclear power plant—have evoked the nuclear spectre and raised fears of accidental catastrophe. These actions do not constitute explicit nuclear threats, but they increase the perceived probability that events could get out of control.

Threats to the Very Existence of the State

Officially, Russian doctrine restricts nuclear use to situations involving existential threats to the state. In practice, public statements have blurred or stretched this threshold. References to “existential danger” are rarely defined, leaving open the possibility that a wide range of developments, from battlefield losses to increased western involvement, could qualify.

Interpretation of nuclear doctrine and Russian strategy is complicated by the distinctly symbolic and ideological character of its security discourse. In Russia, the military, the Orthodox Church, and the state are closely intertwined, and this relationship increasingly extends into the nuclear realm. The growing prominence of religious narratives surrounding Russia’s nuclear arsenal has contributed to an image of civilisational struggle and existential commitment. Clergy are embedded with military units and are depicted blessing intercontinental ballistic missiles; theologians frame nuclear weapons as the ultimate guarantor of Orthodoxy and national survival. Such rhetoric reinforces the perception of a leadership willing to accept extreme risks, thereby cultivating an image of unpredictability.

Many of these signals are not primarily directed at foreign governments but their domestic constituents.

Crucially, many of these signals are not primarily directed at foreign governments but their domestic constituents. Russian nuclear rhetoric has resonated—at least initially—within western domestic debates. Within the EU and NATO, decision-making processes were marked by consultation delays, as Allies with differing threat perceptions and risk tolerances struggled to agree on an appropriate response. In the early days of the war, President Joe Biden framed the central objective of US policy as avoiding World War III, underscoring he was conscious of escalation risks. Taken together, these reactions indicate that nuclear signalling did contribute to one of Russia’s objectives after its initial offensive had stalled: preventing direct western military intervention and confining the conflict to Ukrainian territory.

At the same time, nuclear threats are also directed inward, at the Russian population. Russia’s nuclear arsenal is one of the most unambiguous attributes to its continued great power status. Threatening to use these weapons may serve to reinforce national identity, legitimise the war effort, and project strength. This dual function creates an additional layer of ambiguity. Statements intended for domestic consumption may be interpreted abroad as strategic signals, even when they are not designed as such. Conversely, external audiences cannot easily distinguish between messages aimed at internal mobilisation and those intended as deliberate deterrent signals, complicating their ability to formulate appropriate responses to apparent escalatory steps.

The Limits of Manufactured Uncertainty

In 2022, concerns about escalation contributed to significant western restraint. By 2024, that caution had diminished. Western states approved increasingly advanced weapons systems and relaxed restrictions on their use. Ukrainian strikes on targets in Crimea—and in some cases within the Russian Federation itself—did not trigger the responses earlier Russian rhetoric had implied. This shift reflects a process of learning. As threats are repeated without being carried out, adversaries update their beliefs about intentions and thresholds. Signals that once conveyed the risk of uncontrolled escalation come to appear as calibrated attempts at coercion. As the gap between rhetoric and behaviour becomes visible, threat recipients assign a lower likelihood to escalation slipping beyond control.

External audiences cannot easily distinguish between messages aimed at internal mobilisation and those intended as deliberate deterrent signals.

Ambiguity is inherently fragile: it relies on adversaries’ inability to distinguish between deliberate strategy and genuine risk. As that distinction becomes clearer—through repeated interaction, intelligence, and observation—the coercive leverage of ambiguity diminishes. There is a clear danger in pushing ambiguity too far. Efforts to appear unpredictable or irrational can backfire if they are perceived as manipulative rather than authentic. A well-known example is the ‘madman’ strategy pursued by Richard Nixon during the Vietnam War. Nixon sought to convince North Vietnam that he might act recklessly, but instead reinforced the perception that he was attempting to stage-manage risk, hardening rather than weakening his opponent’s resolve.

Lessons for Interpreting Russian Nuclear Threats

Russian nuclear signalling initially derived its coercive power not from clear commitments, but from ambiguity—the possibility that escalation might slip beyond deliberate control. But ambiguity is a wasting asset. As adversaries learn, observe behaviour, and test boundaries, vague threats lose credibility. The Russian case suggests that nuclear coercion based on ambiguity may well be effective in the short term but is difficult to sustain during prolonged crises.

Ambiguity is a wasting asset.

Over the course of the war, the repetition of Russian threats reduced their novelty and emotional impact, while recurring patterns made them more predictable. Allied governments converged on more consistent assessments of Russian escalation thresholds, reducing internal disagreements within NATO. Similarly, domestic audiences across western countries became habituated to nuclear rhetoric, requiring increasingly dramatic signals to produce the same psychological effect. Crucially, Moscow has avoided taking more concrete escalatory steps—such as visibly altering nuclear deployments—that might have reintroduced some uncertainty.

This does not mean that nuclear risks emanating from Russia have disappeared. On the contrary, the erosion of credibility may introduce new dangers, as adversaries become more willing to test boundaries. And what remains is the lesson that the coercive power of nuclear threats depends not only on capabilities, but on the careful management of uncertainty.

The coercive power of nuclear threats depends not only on capabilities, but on the careful management of uncertainty.

This raises important implications for deterrence theorists, military strategists, and policymakers. If nuclear powers rely on ambiguity rather than clarity, crisis management becomes less about deterring deliberate threats and more about managing performances of a ‘partial loss of control’. This requires attention not only to capabilities, posture changes, and red lines, but to how risk is communicated, perceived, and interpreted across audiences. In an era of eroded arms control regimes and renewed great-power rivalry that is increasingly untethered from rules and norms, understanding how states construct and exhaust uncertainty will be central to managing escalation.

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This article was written for the Lennart Meri Conference special issue of ICDS Diplomaatia magazine. Views expressed in ICDS publications are those of the author(s).