Russia Uses Black Sea Ceasefire Talks to Regain Former Hegemony

Executive Summary:

• The Black Sea is the only theater in which Ukraine is prevailing over Russia in the ongoing war. The Kremlin regards the U.S.-brokered, deadline-driven ceasefire talks as an opportunity to reverse Ukraine’s successes in this theater.
• A maritime ceasefire without demarcation lines and restricting Ukraine’s use of naval drones would let Russia’s reduced but still-dominant fleet return to Sevastopol and the western Black Sea, potentially interfering with commercial shipping again.
• The terms of the latest ceasefire talks apparently protect Russia’s inland energy assets from Ukrainian aerial drone strikes but do not protect Ukrainian ports from Russian air strikes. Military targets in Crimea seem to be off limits for Ukraine under those terms.

The Black Sea, once the front line of Ukraine’s maritime resistance, has become a bargaining chip in the ceasefire process. The United States is the key driver in securing a Black Sea ceasefire scenario as the U.S. diplomatic position has shifted from alignment with Ukraine to equidistant mediation between Ukraine and Russia in the latter’s ongoing war. 

The White House’s immediate priority is to achieve a maritime and air ceasefire in the Black Sea basin, hopefully by April 20, as a waystation toward a comprehensive ceasefire on the Ukrainian mainland that could, in turn, lead to opening peace negotiations, general elections in Ukraine, and signing a peace settlement (The New Voice of Ukraine, March 23). This stage-by-stage approach and open-ended calendar dramatically downsizes the White House’s initial ambition to fix a peace settlement in one fell swoop.

The Black Sea is the only theater in which Ukraine is prevailing over Russia in the ongoing war. Ukrainian naval drone warfare has successfully opened a safe shipping corridor between Odesa and Istanbul, decimated Russia’s fleet and forced its remainder to withdraw from the Sevastopol main base, hiding in distant Novorossiysk (see EDM, August 13, 2024).

Consequently, the Black Sea basin is the quietest theater in this war from autumn 2023 to date (see EDM, March 28). Thanks to Ukraine prevailing here, a U.S.-brokered maritime ceasefire is more attainable than one on the Ukrainian mainland. Russia, however, uses the tripartite U.S.-Russia-Ukraine talks as an opportunity to shape the terms of a maritime ceasefire in Moscow’s favor, to reverse Ukraine’s gains in the Black Sea (see EDM, March 28, April 1).

At this stage, the U.S.-brokered talks raise many unanswered questions not simply for Ukraine but also for Washington’s North Atlantic Treaty Organization (NATO) allies in the Black Sea region.

Scope of the Ceasefire

Russia appears resolved to continue the ground and air war on the Ukrainian mainland even as a maritime and aerial ceasefire is negotiated and eventually declared in the Black Sea. How far a Black Sea ceasefire would extend beyond the water’s edge onto the mainland in Ukraine and Russia, and whether the maritime and mainland domains can be separated from each other for ceasefire purposes, will be hard to determine even technically, let alone in the absence of Russian good faith.

In contrast with the land war, no frontline exists in the Black Sea that could ipso facto become a demarcation line in the event of a maritime ceasefire. Any demarcation line at sea would have to be negotiated from scratch, but Russia has turned this down. A ceasefire without demarcation lines and precluding Ukraine from firing its drones would allow Russia’s still-dominant fleet to return to Sevastopol, prowl around the central and western parts of the Black Sea, and potentially interfere with international and Ukrainian commercial shipping, as Russia made clear at the latest round of talks in Riyadh. The Russian fleet did all that successfully in 2022–2023 without firing a cannon shot at civilian ships. Kyiv has therefore officially warned that it would use its right of self-defense to prevent the Russian fleet from returning to Sevastopol (see EDM, March 28).

Divergent Interpretations of Air Strikes on Civilian Targets

Moscow takes the position that the 30-day aerial ceasefire runs from March 18 and applies to air strikes on each other’s energy infrastructure assets (Russian word: Obekty; объекты) only (President of Russia, March 18). Kyiv, for its part, maintains that the aerial ceasefire runs from March 25 and applies to infrastructure generally, including energy installations (President of Ukraine, March 25). The divergent interpretations stem from separate U.S.-Russian and U.S.-Ukrainian understandings at the talks in Riyadh on March 23–25 and announced by the three sides in separate press releases. The White House then amended its wording to indicate that the aerial ceasefire only applies to the energy sector (see EDM, April 1).

Ukraine’s interest in the Black Sea aerial ceasefire is to protect its sea ports, alongside energy infrastructure, from Russian air strikes. Moscow explicitly rejects this interpretation of the term “infrastructure“ while Washington has not made its official position public (TASS, March 19). Thus, aerial ceasefire restrictions weigh primarily on Ukraine. It must, henceforth, stop its successful drone attacks on Russian oil refineries and related oil industry assets. Most of those targets are located deeply inside Russia but seem nevertheless to be protected (as Moscow claims) by a far-and-wide application of the Black Sea ceasefire. On the other hand, Russian air strikes on Ukrainian cities and ports located directly on the Black Sea littoral do not seem to be considered as ceasefire violations (Ukraiynska Pravda, March 26).

Crimean Military Targets: Ceasefire-Protected?

Ukraine has already demonstrated that it is possible to render Russia’s hold on the Crimean Peninsula untenable through precision drone and missile strikes on military targets. This objective presupposes continuing British and French ammunition deliveries to Ukraine as in 2023–2024. A ceasefire that precludes Ukraine from striking Crimea would, in effect, stamp and seal Russia’s hegemony in the Black Sea basin. The United States and NATO would, in that case, have to address the concerns of their allies Romania and Bulgaria more proactively than they have done to date, and with additional resources.

The Russian-built Kerch Strait Bridge, operational since 2020, qualifies as a legitimate military target, critical to resupplying Russian forces based in Crimea. The Kremlin has almost certainly asked the United States that the ceasefire should also protect that bridge. Kremlin spokesman Dmitry Peskov seemed to hint at this following the talks in Riyadh (TASS, March 31).

Oil Exports From Russia to Continue Unimpeded

Ukraine has never interfered with oil exports from Russia via the Black Sea in any way since the beginning of the war.

Exports of crude oil and oil products from Russian ports on the Black Sea and Azov Sea are massive in quantity and proceed unimpeded in pre-scheduled, steady monthly volumes. Exports by tanker to destinations outside the Black Sea amounted to 12.9 million metric tons, carried by 181 tanker runs, in February 2025, the most recent month for which statistics are available (Black Sea Institute of Strategic Studies, Monitoring Group, Black Sea News, March 5). That total volume included 6.9 million metric tons of oil extracted in Kazakhstan and pumped through the Tengiz-Novorossiysk pipeline to a dedicated offshore export terminal there (oil originating in Kazakhstan is not subject to Western sanctions). Additionally, smaller volumes are delivered within the Black Sea to Romania and Bulgaria (Black Sea Institute of Strategic Studies, Monitoring Group, Black Sea News, April 5).

Interim Outlook

U.S.-facilitated talks on a Black Sea maritime and aerial ceasefire are set to continue and possibly accelerate. Meanwhile, Russian offensive actions will continue unabated on the Ukrainian mainland and the airspace above it. The Donald Trump administration sought a comprehensive, unconditional ceasefire on land and at sea. Moscow, however, has separated the two theaters, along with Russian preconditions for a maritime ceasefire (see EDM, March 21).

Moscow regards a Black Sea ceasefire as an opportunity to reverse Ukraine’s successes in the maritime war. Merely by discussing the possibility of a Black Sea ceasefire, Russia has earned protection of its energy assets inland from Ukrainian air strikes while refusing a mirror arrangement for Ukrainian sea ports. Bargaining for as long as necessary over the maritime ceasefire terms, Moscow likely intends to gain time for biting off more Ukrainian territory and attrite Ukraine’s material and human resources in the continuing land war.