When the Kremlin launched its full-scale invasion of Ukraine in 2022, Russian strategic thinking was anchored around a distinct hierarchy of adversaries and instruments of power. At the time, Moscow viewed the United States as its principal geopolitical rival, an arch-adversary that it believed was actively orchestrating Kyiv’s efforts to impose a strategic defeat on Russian forces. In this earlier worldview, European capitals and the NATO alliance were largely perceived as subordinate extensions of American power, useful primarily as logistical hubs or political echoes of Washington’s foreign policy. To manage this environment, the Kremlin relied heavily on nuclear saber-rattling, utilizing overt muscle-flexing as a primary and efficient mechanism for exerting coercive pressure across the continent.
Today, after years of intense warfare and amid an evolving international landscape shaped by the second Trump administration, the mental map guiding Russian national security strategy has undergone a profound transformation. According to influential defense intellectuals and policy experts close to the Kremlin, Moscow now views Europe, rather than the United States, as its primary geopolitical adversary. This monumental shift has driven the Russian defense establishment to embrace a strategic concept known as "castling" to address perceived vulnerabilities and threats on its western borders.
Concurrently, Moscow now attributes a new level of strategic agency to Europe itself. This reassessment has been catalyzed by the dramatic military modernization programs underway in numerous European countries, alongside a growing appetite among certain European leaders to develop, expand, or extend their own independent nuclear deterrent capabilities. Furthermore, Russia’s traditional reliance on nuclear coercion is increasingly giving way to a sophisticated new doctrine of nonnuclear strategic deterrence, which leverages advanced conventional precision-strike systems specifically aimed at European targets.
While these emerging schools of thought do not necessarily require formal endorsement in official security doctrines to carry weight, they remain deeply influential. Over the past decade, ideas circulating freely within Russia’s national security establishment have consistently shaped how officials frame problems, define strategic options, and ultimately execute major foreign policy and military choices. As Moscow navigates future escalations, manages ongoing competition, and eventually approaches any serious diplomatic negotiations to end the war in Ukraine, these three core shifts in strategic thinking will inevitably play a foundational role.
As Washington steps up its own diplomatic efforts to engage the Kremlin, it is actively negotiating with a Russian leadership whose underlying worldview has evolved dramatically since the outbreak of the war. For the United States, comprehending this new Russian mental map will be vital not only for discovering a viable off-ramp to the conflict but also for mitigating the severe risk of inadvertent escalation between Russia and Europe, thereby securing long-term strategic stability across the continent.
The Pivot to Europe
Among the most notable developments in Russian strategic discourse over the past year is the popularization of the concept of "castling." Borrowed directly from the game of chess, the term describes the repositioning of pieces to optimize a player’s defensive and offensive posture. Russian defense experts have adopted the metaphor to articulate a new geopolitical reality: for the first time since the end of the Second World War, they argue, Europe has eclipsed the United States as Russia’s foremost geopolitical adversary. In Moscow’s eyes, European nations have become the primary engines driving Ukraine’s military capacity, political resolve, and strategic resilience. It is Europe, rather than Washington, that is now viewed as having made Ukraine its proxy to pursue the strategic defeat of the Russian state.
Consequently, Russian strategists argue that Moscow must direct its coercive pressure squarely at Europe—targeting its political elites, decision-making centers, and critical national infrastructure. By doing so, Russia aims to instill what analysts in Moscow term "deterring fear" into European calculations, fostering a deep-seated reluctance among European leaders to antagonize Russia through continued military and financial support for Ukraine. Proponents of this view suggest that such a posture will help rebuild credible long-term deterrence for a prolonged competition with the West, which is now seen as centered firmly in Europe.
Crucially, this strategy of castling does not imply a fundamental change in Russia’s overarching political and military objectives. Those goals remain identical to the demands articulated by Russian President Vladimir Putin at the time of the 2022 invasion: preventing any future NATO enlargement to Ukraine and other former Soviet republics, rolling back the alliance’s eastern military flank, and heavily restricting NATO exercises alongside conventional and nuclear deployments near Russia’s borders. The critical difference lies in the target; Moscow now believes that coercive pressure must be applied directly to European capitals rather than Washington to achieve these ends.
Alongside this revised assessment of Europe, Russian strategists have interpreted the Trump administration’s foreign policy posture as clear evidence that Asia has permanently replaced Europe as the primary theater of U.S. strategic competition. They point to Washington’s visible reluctance to heavily back Ukraine, its expressed desire to terminate the conflict swiftly, and its continued diplomatic overtures toward the Kremlin. Decisions such as applying targeted sanctions relief to Russia while increasing pressure on Kyiv have only served to amplify this viewpoint within Moscow’s analytical circles.
Furthermore, Russian strategists assume that Washington is actively seeking to consolidate its primacy within the Western Hemisphere while viewing Beijing, not Moscow, as its ultimate long-term threat. From this perspective, the United States is attempting to reduce its military and political commitments in secondary theaters like Europe and the Middle East to concentrate its finite resources on containing China. While major U.S. military engagements elsewhere are viewed in Moscow as temporary deviations from this broader strategic realignment, the core assumption remains firmly entrenched in the Kremlin’s strategic calculus.
Nuclear Curiosity
Paralleling the pivot toward Europe is a growing fixation within Russian defense circles on what analysts describe as Europe’s "nuclear curiosity" and burgeoning military assertiveness near Russia’s borders. Russian strategists have expressed acute concern over the ongoing modernization of British and French nuclear arsenals and the apparent readiness of Paris and London to wield those capabilities more assertively. Moscow is particularly attuned to discussions surrounding the potential extension of French or British nuclear guarantees to other European nations, as well as the consideration by non-nuclear European capitals of developing sovereign nuclear options.
Russian security sources increasingly categorize nations like Germany, Poland, and the Nordic-Baltic states as "nuclear curious," noting instances where regional officials have voiced support for local deterrent capabilities or sought shelter under alternative nuclear umbrellas. The public discourse by various European leaders regarding extended deterrence as a potential substitute for the historical U.S. security guarantee has been monitored closely by Russian military analysts.
From Moscow’s perspective, any tangible step by a non-nuclear European state to cross the threshold toward becoming an independent nuclear power represents a major red line that could constitute a legitimate casus belli. Moreover, this perceived escalation on the nuclear front is occurring simultaneously with the deployment of advanced conventional deep-strike precision weapons near Russian borders. While NATO views this heightened European posture as a necessary hedge against shifting U.S. commitments, Moscow interprets it as an alarming signal that Europe might eventually acquire the capability to execute disarming counterforce strikes against Russia’s nuclear arsenal or launch decapitation strikes against its leadership.
These developments are viewed by Russian analysts as compelling evidence of Europe’s growing strategic autonomy from Washington. Historically, Moscow largely dismissed Europe as a dependent staging ground for American military power. That foundational assumption is now crumbling. Combined with the conviction that Europe is Russia’s primary adversary, the continent’s rising independence in both nuclear and conventional domains has become a central variable in Russian strategic planning. Defense intellectuals in Moscow argue that Russia must adapt its posture to contain this trend, developing new tools to keep Europe at bay and coerce it safely below the nuclear threshold.
Menacing Gestures
To align with this updated mental map, Russian military officers and defense theorists have spent the past year intensely examining how to make Moscow’s coercive strategies more effective. During the initial phases of the war, traditional nuclear saber-rattling and hybrid warfare tactics proved insufficient to prevent Ukraine’s Western allies from funneling massive amounts of financial aid, advanced weaponry, and vital intelligence to Kyiv. Nor did those coercive measures deter Ukrainian cross-border incursions into Russian territory, strikes on symbolic domestic targets, or attacks on vital strategic infrastructure.
Today, while NATO remains heavily focused on countering Russia’s cross-domain hybrid campaigns, Moscow is simultaneously developing a parallel instrument known as nonnuclear strategic deterrence (NNSD). For Russian military authors, NNSD involves utilizing advanced conventional capabilities—such as precision-guided munitions, loitering munitions, ballistic and cruise missiles, hypersonic weapon systems, and electromagnetic or high-power microwave systems—to compel and deter adversaries without resorting to nuclear weapons.
Conceptually, NNSD falls within what Russian experts describe as the "art of strategic gestures," a diplomatic and military euphemism for signaling intent through the actual or threatened use of force. While Russian strategists have explored conventional alternatives to nuclear deterrence for decades, these concepts remained largely theoretical prior to the 2022 invasion. The grueling reality of the war in Ukraine has transformed NNSD into an operational reality.
Although Russia has routinely deployed tactical ballistic missiles, cruise weapons, and hypersonic systems alongside drones and maneuver warfare throughout the conflict, many Russian analysts felt these efforts underdelivered during the war’s early years. As the conflict settled into a protracted war of attrition, Moscow shifted its focus toward massive, synchronized ballistic salvo strikes, including the combat deployment of intermediate-range Oreshnik ballistic missiles against strategic targets.
Drawing directly from these operational lessons, Russian military theoreticians now envision NNSD as a framework centered on deep, highly coordinated precision strikes against an adversary’s critical military, political, and economic infrastructure. Proponents suggest this strategy should be directed not only at Ukraine but also at its principal European backers. The growing prominence of NNSD is reflected in institutional publications; since 2025, Military Thought, the flagship journal of the Russian General Staff, has published numerous articles exploring the doctrine, while various branches of the Russian armed forces compete to refine and claim ownership over its execution.
The Coercion Threshold
The Kremlin initially launched its war in Ukraine with the broader objective of compelling Europe to fundamentally reshape its regional security architecture. Yet, the strategic landscape confronting Moscow today appears even more challenging than the one it sought to alter in 2022. Washington must recognize that the Kremlin views the conflict in Ukraine not as an isolated local dispute, but as a central battleground in a much wider struggle over the future of Europe’s security order. Any American-led diplomatic initiative aimed at securing a negotiated settlement must contend with Moscow’s emerging castling logic and its deep-seated anxieties regarding European re-militarization.
A diplomatic settlement that addresses immediate battlefield dynamics while leaving Moscow’s broader structural grievances with Europe unaddressed will likely serve as nothing more than a temporary pause in a larger, ongoing confrontation. Washington must understand that Russia’s reliance on nonnuclear coercion has evolved into a permanent feature of its long-term deterrence strategy against Europe, rather than a temporary tactic tied exclusively to the war in Ukraine.
Even if Moscow engages seriously in diplomatic negotiations to halt the fighting, it is widely expected to continue applying military coercion against both Ukraine and Europe. The Kremlin will likely use calibrated attacks, infrastructure strikes, and diplomatic engagement simultaneously to shape the terms of any final settlement, test its evolving theories of nonnuclear deterrence, and force European capitals to renegotiate the continent’s security architecture. In response, European nations—harboring deep doubts regarding the long-term reliability of U.S. security commitments and eager to demonstrate their own strategic resolve—may feel compelled to escalate in kind.
Washington must therefore prepare for the distinct possibility that intensified diplomatic efforts to end the war will coincide with heightened security risks across Europe. Given that the prevailing relationship between Russia and Europe is defined by pervasive mutual suspicion, deep-seated hostility, and an underlying expectation of prolonged conflict, the danger of inadvertent escalation remains alarmingly high. Actions undertaken by either side simply to signal resolve or establish negotiating leverage risk being systematically misread, triggering a dangerous action-reaction cycle that actively erodes deterrence precisely when all parties are seeking a diplomatic off-ramp.
Both Europe and Russia now face the delicate challenge of bolstering their respective deterrent postures without crossing a dangerous threshold beyond which further military signaling could catastrophically expand the war. For Washington, the primary task extends beyond merely mediating the text of a peace deal; it will require successfully choreographing delicate negotiations amid ongoing military friction. U.S. officials must learn to anticipate coercive maneuvers from all sides without prematurely dismissing them as a rejection of diplomacy, ensuring that the escalating security dilemma does not derail the path toward lasting stability.
