This section explores how Russia’s dominance in the Black Sea affects regional stability and European resilience. Russia’s overarching strategic objective in the Black Sea is driven by its desire to reach the status of a recognised global power and extend its sphere of influence. The export and trade of its vast wealth of hydrocarbon resources and agricultural products give it the necessary leverage. To exploit this to the fullest, Russia requires assured access to the global network of maritime shipping routes and pipelines.

Three priorities define Moscow’s approach, the foremost being market access: sustaining Russia’s economic leverage at home and abroad. By securing access to key energy corridors such as TurkStream and BlueStream, Russia maintains its connectivity to European gas markets via Türkiye, thereby reinforcing its economic leverage. Agriculture is another important factor in Russia’s long-term economic strategy, with Rostov and Krasnodar as key export hubs.[19] Yet Ukraine’s more efficient and cheaper production poses a competitive challenge.

Second, coercive leverage: by controlling maritime space in the Black Sea’s northern littoral zones, Russia can constrain Ukraine’s food exports, a strategy that predates the full-scale invasion. Even before 2022, Ukrainian vessels faced obstacles in the Sea of Azov. Capturing or blockading Odesa would not only cripple Ukraine’s economic potential and recovery but also secure Russia’s land access towards Moldova, extending its military presence on the border with the EU.

Third: beyond the immediate economic rationale, securing access to warm-water ports along the Black Sea supports Russia’s broader strategy for power projection into the Mediterranean, the Middle East, and Africa.

To secure its objectives, Russia does not shy away from using various disruptive measures that it has in its arsenal. Its 2022 Maritime Doctrine frames its stance as a “total hybrid war with the Collective West”,[20] echoing the 2021 National Security Strategy’s emphasis on resisting external pressure, defending internal unity, and shaping a new global order. This strategic thinking underpins Russia’s military actions, from the ongoing occupation of Transnistria in Moldova since 1992, to the 2008 occupations of Abkhazia and South Ossetia in Georgia, the 2014 annexation of Crimea, and the 2022 invasion of Ukraine. Through hybrid operations, Russia exploits divisions within Europe to delay or fracture coordinated responses, allowing it to project power despite its own relative military weakness[21] vis-à-vis the NATO alliance.

In assessing the Russian threat, it is essential to distinguish between Moscow’s goals and the means it employs, as they are carefully aligned. Russia still behaves as a rational actor, adapting its methods according to specific circumstances. At the lower end of the spectrum, it relies on influence operations – manipulating public opinion, media narratives, historical facts, corruption, and electoral outcomes. Efforts to sway elections in Moldova or to cultivate pro-Russian elites in Bulgaria and Romania illustrate how Moscow seeks to steer littoral states towards policies favourable to its interests. When these efforts fail and states lean away from Russia, it escalates its activities. Its tactics then shift to electronic jamming, harassment and “inspections” in contested waters, deniable sabotage of seabed infrastructure, military build-ups, and ultimately direct intervention. This incremental approach shows how hybrid measures are scaled according to the level of resistance encountered and the likelihood of a proportional response.

Figure 7 offers a visual overview of the components of a destabilising (hybrid) campaign. While not intended as a literal playbook, it illustrates the range of measures an aggressive actor might employ, each allowing plausible deniability, to achieve influence, intimidation, and coercion in pursuit of a broader objective. For Russia, that objective is the achievement and broad recognition of its great power status, along with acceptance of its claimed sphere of influence. This process is not strictly linear: an actor can escalate or de-escalate depending on the campaign’s progress. The steps shown on the ladder are likewise not exhaustive. New tactics continually emerge, and existing ones evolve to maximise early impact while remaining below the threshold of armed conflict and maintaining deniability, thereby hindering attribution.

Because the effects are constantly assessed and refined through lessons learned elsewhere, the nature of these actions keeps shifting, making effective countermeasures hard to design. Even when specific activities can be attributed, defending against them is challenging, and opportunities for retaliation remain limited.

The Black Sea offers fertile ground for such operations. Its size and complexity of overlapping interests of the littoral states facilitate grey-zone tactics more easily than in the Baltic. Recent examples include Russian military drills in Bulgaria’s EEZ, followed weeks later by a mine explosion off Romania’s coast.[23] Russian aircraft have monitored civilian vessels in Turkish waters, while Moscow’s manipulation of grain routes unsettles food-importing regions and indirectly affects Europe through migration pressures – underlining its readiness to test boundaries.

Russia calibrates its hybrid actions carefully, avoiding measures that could trigger a direct clash with Türkiye, whose control of the Bosphorus and Dardanelles represents a restraint on Russian naval mobility and energy and other exports. Furthermore, destabilising ports in Bulgaria or Romania, crucial nodes for oil and gas exports, would be counterproductive and costly. Yet Moscow escalates where it expects muted responses. Therefore, the emergence of offshore gas projects in the Black Sea does raise the risk of targeted disruption and this affects Romania and Bulgaria, if Moscow views them as competitive threats. Should Russia’s access to EU energy markets shrink further – or rival producers expand exports at scale – the likelihood of such provocations will only grow. From this perspective, exploring ways to engage Türkiye in a regional coordination mechanism could sharpen deterrence by increasing the risks Russia must factor into its cost-benefit calculus.

Russia’s hostility needs to be recognised as a long-standing strategic policy, not a temporary aberration. Moscow’s approach predates Crimea’s annexation in 2014 and reflects a sustained intent to weaken its European neighbours. Downplaying this threat has allowed Russia to entrench itself, build alliances, and expand its means of coercion, turning what was viewed as a regional issue into a transatlantic challenge. Developing effective hybrid response measures mirroring the escalation ladder will aid in countering Russian offensive tactics,[24] and address incidents such as drone incursions over Poland, helicopter violations in Estonia, or the jamming of aircraft communications – these responses must be prompted to prevent escalation and further provocations.