The Black Sea After the War: Will It Become a New Point of Destabilization for NATO?

The war has changed the geography of naval power, but it has not eliminated the threat. Russia’s presence in the Black Sea has not disappeared – it has transformed.

Following the partial destruction of Russia’s Black Sea Fleet, the loss of flagships, and the withdrawal of Russian ships from Sevastopol, an illusion has emerged that the maritime threat to Ukraine and NATO has significantly diminished. However, this illusion is dangerous. Russia’s presence in the Black Sea has not disappeared – it has transformed. And this transformation does not reduce the risks for the Alliance; it merely changes their form.

The fleet has ceased to be a demonstration of strength but has become an instrument of hybrid destabilization – from missile strikes to mining waters and blockading ports. For this reason, the Black Sea risks turning into a new point of turbulence for NATO even after the hot phase of the war in Ukraine concludes.

The Black Sea Is Not Just About Ukraine, But About NATO’s Entire Eastern Arc

The geopolitical role of the Black Sea extends far beyond the context of the war in Ukraine. It is a strategic frontier between NATO (through Turkey, Bulgaria, and Romania) and aggressive Russian militarism. Even if the Kremlin is unable to maintain dominance in Sevastopol, it retains footholds in Novorossiysk, Abkhazia (an occupied part of Georgia), and is establishing bases for kamikaze drones along the coasts of Crimea and Kuban.

The situation is further complicated by the fact that Turkey, the Alliance’s main naval player in the region, pursues a policy of “balancing” – between NATO membership and personal agreements between Erdoğan and Putin. This limits the Alliance’s operational capabilities. Bulgaria and Romania lack sufficient resources to ensure a consistent naval presence, while the formal restrictions of the 1936 Montreux Convention prevent NATO countries from deploying full-fledged naval forces in the Black Sea during peacetime.

Thus, even after Ukraine’s victory, the threat will persist – in the form of missile launches from the sea, cyberattacks on navigation systems, the use of unmanned boats, and naval mines. The Black Sea will remain an arena of undeclared but continuous struggle.

What Remains of the Black Sea Fleet – and Why It’s Still a Problem

As of 2021, Russia’s Black Sea Fleet had over 70 combat units, including cruisers, frigates, submarines, missile boats, and auxiliary vessels. After 2022, the losses became significant: the flagship Moskva was destroyed, at least 25 vessels were damaged or disabled, and the infrastructure in Sevastopol was severely impacted. However, Russia has not ceased its activities – relocating ships to Novorossiysk, using submarines to launch Kalibr missiles, and creating a hybrid drone fleet – all of this indicates that the fleet is adapting to a new concept of warfare.

In particular, the Black Sea Fleet is increasingly avoiding open confrontation and focusing on gray zones – sabotage, pressure on shipping, the spread of naval mines, and intimidation of commercial operators. In the future, the emergence of new Russian underwater platforms for electronic warfare and deep-sea operations is likely. In other words, the threat has not disappeared – it has simply become less overt.

The Black Sea: A Future Front of Informational-Economic Warfare

After the end of ground combat, Russia is likely to shift the focus of its hybrid influence to the maritime domain. The ports of Odesa, Pivdennyi, Constanța, and Burgas are criticality points for food exports, energy, and trade. Destabilizing maritime routes is a cheap way to hinder Ukraine’s growth, sow panic among investors, and provoke political destabilization in Moldova, Bulgaria, or Romania.

Moreover, Russia’s ambitions regarding the Danube Delta should not be overlooked. Control over the Danube’s mouth is not only about economics but also about political influence over Moldova, Romania, and Hungary. This is why Russian attacks on Reni, Izmail, Ukrainian barges, and grain elevators are not just strikes on logistics – they are a strategic signal: the Black Sea is not closed to us.

Why NATO Will Need to Be Present Here – for the Long Haul

Even after Ukraine’s victory and the potential de-occupation of Crimea, the Black Sea will not automatically become safe. Like the Baltic Sea after Sweden and Finland joined NATO, it will require constant attention. The Alliance will need to create new security formats: regular patrols, coordination centers, navigation monitoring, joint exercises, and possibly the deployment of missile defense components. Otherwise, the vacuum will be filled not by peace but by new actors – flying the Russian flag or operating under the guise of private entities.

In particular, Ukraine will need integration into NATO’s maritime monitoring programs, joint exercises with Turkey, Italy, and France, and the supply of new platforms – both strike boats and reconnaissance vessels. If the Black Sea remains a “gray zone,” Russia will once again use it for pressure, terrorism, and political sabotage.

Ukraine’s victory will change the military geography of the region but will not eliminate the threat. The Black Sea will remain an arena of hybrid warfare – for routes, influence, logistics, and signals of strength. Russia will not leave, even if it loses Crimea. This is why NATO must think ahead: not how to respond to escalation, but how to prevent it. Only an active naval presence, integration with Ukraine, control over the information space, and a proactive maritime strategy can ensure stability in a region that has ceased to be a periphery.

Dmytro Levus, foreign policy expert, analyst at kyiv-based United Ukraine Think Tank