Ukrainian Strikes on Russian Tankers: Maritime Pressure and the Stranglehold on Crude Revenues

Ukraine’s overnight attacks upon two Russian oil tankers travelling through the Black Sea and the Sea of Azov represent another step in Kyiv’s steady evolution towards a maritime strategy designed to undermine the financial lifeblood of the Kremlin’s war. Russian crude exports remain the single most important source of foreign currency revenue for Moscow. She relies upon them to pay for weapons, ammunition and the subsidised war economy that sustains her invasion. Any Ukrainian action that raises the cost, risk or logistical burden of exporting crude therefore strikes at the very system that keeps the conflict alive.

The latest attacks are strategically significant because they target the Russian Federation’s export chain at a vulnerable point. For all her efforts to redirect crude away from European markets and towards Asia, Russia remains dependent upon maritime transport. The Black Sea and the Sea of Azov are internal waters from Moscow’s perspective, yet geography makes them chokepoints. Tankers must sail predictable routes, many of which pass within reach of long-range Ukrainian maritime drones, one-way explosive vessels, or air-launched stand-off weapons. Even moderate disruption creates disproportionate economic pain because oil is a volume trade. A single tanker may carry cargo worth tens of millions of dollars; damaging one vessel can ripple through insurance premiums, naval escort requirements and export scheduling for weeks.

Ukrainian strategy recognises these asymmetries. Kyiv’s naval capacity in conventional terms is slight, because the Russian Black Sea Fleet destroyed much of the Ukrainian surface navy in 2022. Instead Ukraine has built a fleet of remotely guided maritime drones capable of traversing hundreds of kilometres. These drones blend stealth, low cost and surprise. They have already driven much of the Russian fleet away from Crimea’s western coast and forced Moscow to disperse warships and adopt static, defensive postures. The same tools can now be used against the oil export network.

The immediate question is whether such attacks meaningfully reduce the revenues Moscow draws from crude exports. Ukraine’s aim is seldom to sink tankers outright, because that would provoke diplomatic backlash from oil-importing states and raise marine pollution concerns. Instead the objective is to compromise hull integrity, disable propulsion systems, or force an evacuation that renders a vessel temporarily unusable. Every damaged tanker triggers a cascade of secondary effects. The first of these is the insurance market. The London market, which remains the centre of global marine underwriting, has repeatedly raised premiums for vessels calling at Russian ports. A successful Ukrainian attack pushes those premiums higher again. In many cases, insurers will refuse cover entirely, which leaves shipowners dependent upon insurance arrangements for shadow fleets financed through opaque structures close to the Kremlin. These fleets are less reliable, more accident prone and more costly to operate.

Higher costs feed directly into the price Moscow must discount when selling crude. Russia already charges substantial reductions to attract buyers such as India and China. Each additional maritime risk pushes that discount deeper, particularly effective at a time of low global oil prices. The second consequence is logistical. Damaged tankers require repair facilities, which are scarce in the Black Sea and limited further by sanctions. Repair queues disrupt export schedules and force Russia to store unsold crude in onshore facilities. Storage limits exist, however, and once tanks fill, export bottlenecks depress output. Russian oil companies cannot simply turn off production; maintaining pressure in oilfields requires continuous pumping. Disrupted exports can therefore push operators into technically hazardous territory or compel them to flare or waste crude.

The third effect concerns naval resources. Protecting tankers requires escorts, surveillance and predictable patrol patterns. Russia has already diverted corvettes, patrol boats and aircraft to protect the Kerch Strait and the approaches to key ports. Each additional escort is one less vessel available for strikes on Ukrainian infrastructure or for defending Russian positions along the coast. Ukraine’s strategy forces Russia to fight a maritime war of attrition at disproportionate cost.

The broader impact of these attacks is psychological and diplomatic. They shatter the Kremlin’s narrative that the Black Sea and the Sea of Azov are secure Russian domains. They also create uncertainty amongst foreign charterers, many of whom face domestic political pressure not to be seen facilitating Russian exports. Even if tankers continue to sail, hesitation and slower loading cycles reduce throughput.

The long-term effectiveness of the strategy depends on Ukraine sustaining an industrial base capable of producing maritime drones in high numbers. Fortunately Ukraine has become adept at dispersed production, using small workshops across the country to avoid presenting easy targets. Western assistance can further strengthen this approach, particularly through the provision of satellite imagery, long-range communications systems and spare parts that increase the endurance of unmanned vessels. The Kremlin, for her part, has limited technological flexibility. Her shipbuilding industry is constrained by sanctions and chronic shortages of imported components. Her naval command must defend an ever-expanding list of high-value maritime targets without increasing the fleet’s size. Such dynamics favour Ukraine over time.

It is unlikely that attacks on individual tankers alone will cripple Russian crude revenues, because Moscow has become proficient at using shadow fleets and informal export routes. Yet the cumulative pressure matters. Each successful strike raises doubt amongst shipowners, brokers and refiners. The result is a gradual tightening of the export environment. Russia earns less for each barrel of crude and she spends more protecting the supply chain. The margins that fund her war contract slowly.

As winter approaches, Ukraine’s maritime campaign shows that she is not restricted to defensive posture on land. She can shape the conflict’s economic dimension, disrupt Russian revenue streams and impose financial attrition upon an adversary with deeper pockets but far less strategic agility. These tanker strikes demonstrate that ingenuity and persistence can challenge the very foundations of Moscow’s war economy.