Russian President Vladimir Putin has threatened to seize European vessels if the European Union proceeds with plans to detain Russian merchant ships and sell their cargoes. The warning, delivered on Wednesday during a visit to a Russian warship involved in Pacific Fleet exercises, represents one of Moscow’s most direct maritime retaliation threats since European governments intensified enforcement against Russia’s so-called shadow fleet.
Putin said Russia would not necessarily respond in the same waters where a Russian vessel was detained. Instead, he suggested that Moscow could act wherever it considered a response necessary, including areas under the operational responsibility of Russia’s Pacific Fleet.
“We will be forced to respond in kind,”
Putin said, warning that Russian retaliation could take place
“not necessarily in those waters where raids on our ships and vessels are planned, but wherever we ourselves deem it necessary and appropriate.”
This statement was made by the Russian President when he said that the European plan was a violation of commercial shipping and that Western governments were guilty of breaking the international maritime law. He added that the governments in some countries were trying to limit the movement of ships belonging to Russian companies, and even went ahead to seize the ships and sell their cargo.
“This is, of course, nothing other than piracy and robbery,”
Putin said.
“And if this begins to be put into practice, we shall be forced to respond in kind.”
Language used was conditional. He did not declare that Russia had started to seize ships belonging to Europe. Neither did he name any particular ship or country which could be a victim. The message delivered by Putin was a message that was meant to dissuade the European Union from seizing the cargoes of Russians.
The dispute behind the threat
This conflict is all about enforcing sanctions on Russia’s shadow fleet – a wide range of tankers and other commercial vessels said to help Russia transport oil while bypassing Western restrictions. Most of these vessels operate under flags of convenience, having unclear ownership or changing their flag regularly. European states claim that the vessels of the shadow fleet reduce the efficiency of sanctions introduced after Russia’s invasion of Ukraine. Moreover, according to them, many tankers of the shadow fleet are old, uninsurable and even environmentally unsafe. But the government of Russia considers the shadow fleet concept as a politically driven one aiming at the legalization of the intervention into Russian connected trade. The conflict became especially acute after the EU imposed new sanctions and measures related to them in 2026. The EU has become more and more focused not on traditional methods such as port bans or asset freezes but on inspections, tracking and restricting the maritime services. It is not only tankers that carry the Russian oil but the vessels that refuel them or provide them with any other help.
Russia views this policy as an attempt to impose a naval blockade without a formal declaration of war. European governments describe it as sanctions enforcement and protection of maritime safety. The difference between these two interpretations is at the heart of the legal and political confrontation.
EU naval enforcement
In June, the EU expanded the mandate of Operation EUNAVFOR MED IRINI in the Mediterranean. The mission was initially established to assist with enforcement of the United Nations arms embargo on Libya, but its responsibilities were broadened to enable EU naval forces to stop, board and inspect foreign vessels suspected of involvement in Russia’s shadow-fleet operations.
The expansion of operations has become a matter of concern for the authorities in Moscow due to the fact that the naval forces of Europe are becoming increasingly involved in the monitoring and possible detention of the ships. Russia insists that European states can neither independently formulate a new category of ships nor use this designation as an immediate reason for their boarding in international waters.
Based on the existing statistics, it is clear that the actions of Europeans are currently focused more on monitoring rather than seizing the vessels in large numbers. In June 2026, according to the report, the Operation IRINI hailed 434 ships and performed two flag verification boardings as well as three consensual “friendly approaches”. Such data is necessary because they show the difference between the rhetoric used by politicians regarding the policy and the implementation of such activities.
The potential turning point would come if European authorities detained a vessel, confiscated its cargo and sold or transferred the proceeds. Such an action would be far more consequential than denying a ship access to European ports or prohibiting companies from providing it with insurance, fuel or other services.
The size of Russia’s maritime network
The EU’s sanctions campaign has expanded rapidly. The bloc’s April 2026 package listed 632 vessels connected with Russia’s shadow fleet. The EU then added another 41 vessels in its 21st package adopted in July, bringing the total to more than 670 designated ships, according to reports. The figures differ slightly between institutions because of differences in counting methods and changes to sanctions lists. Some assessments count only sanctioned tankers, while others include support vessels, ships involved in ship-to-ship transfers and vessels suspected of providing logistical assistance.
The economic significance of the network is substantial. The Centre for Research on Energy and Clean Air estimated that sanctioned shadow tankers carried approximately 54 percent of Russia’s seaborne oil exports in June 2026. The Kyiv School of Economics also reported that 185 loaded shadow-fleet tankers were active in Russian oil exports in May.
The ageing condition of much of the fleet is another concern. KSE estimates cited in recent reporting indicated that roughly 92 percent of the relevant tankers were more than 15 years old. Older vessels are not automatically unlawful, but their condition, insurance status, ownership arrangements and maintenance records can create additional risks for coastal states and maritime authorities. The EU argues that the combination of sanctions evasion, inadequate insurance and environmental exposure justifies stronger action. Russia maintains that these concerns are being used to disguise an effort to obstruct its energy exports and weaken its wartime economy.
Russia signals a wider response
Putin’s remarks were accompanied by a warning from Viktor Liina, commander of Russia’s Pacific Fleet. Liina told the Russian president that the navy was prepared to inspect and detain commercial vessels linked to “unfriendly states.”
According to accounts, Liina stated that the Russian forces can inspect the foreign ships and can react against the ships related to the Western naval system. He also added that the European nations themselves make use of flags of other nations and complicated ownership structure while transporting goods. Mention of Pacific Fleet gives the geographical aspect to the issue. The enforcement efforts by the EU are mainly restricted to the Mediterranean region, however, Putin’s warning makes it clear that the Russian counter-efforts might be taken up in other parts of the maritime world as well.
“The Russian response wouldn’t necessarily come in the waters where the Russian ships were seized,”
Putin said, adding that Moscow could act
“in any area where we see it as necessary and appropriate.”
Russia has also accused NATO of deploying weapons systems in the Asia-Pacific region that threaten its security. That accusation, made in the context of the Pacific Fleet exercises, links the commercial shipping dispute to Moscow’s broader narrative of confrontation with the United States and its European allies. The danger is that an operation presented by one side as sanctions enforcement could be interpreted by the other as an attack on national sovereignty. If Russian naval forces attempted to board a European-flagged or European-linked merchant ship in retaliation, the incident could rapidly become a military and diplomatic crisis.
The international-law question
Whether or not such seizures were legal would depend on the exact circumstances. Seizure could be defined as one of several actions, such as boarding and inspecting, temporary detention, denying access to port, seizing of goods, or confiscating a ship. A government usually enjoys more power within its territorial waters or ports than on the high seas. It would also depend on whether the ship was stateless, was flying the wrong flag, evading sanctions, carrying prohibited cargo or acting on the orders of the flag state. According to the Russian side, the EU cannot consider the sanctions regulations as a global license to seize commercial ships on the high seas. According to Moscow, any attempt to seize the vessels or cargos of Russia without any legal basis would be piracy or theft.
The EU’s position is that sanctions are lawful restrictive measures and that designated vessels can be denied access to ports and services. European governments also rely on maritime-safety regulations, flag-state powers, port-state control and investigations into false registration or sanctions violations. The legal dispute would become especially contentious if an EU member state detained a vessel outside its territorial waters without the consent of the flag state. The outcome would depend on the vessel’s registration, ownership, cargo, location and the precise authority invoked by the boarding state.
Putin’s claim that any European seizure would automatically constitute piracy is therefore not an established legal fact. It is Russia’s official political and legal interpretation. At the same time, the EU’s designation of a vessel as part of the shadow fleet does not automatically settle every question about the legality of boarding, detention or confiscation.
Possible consequences for shipping
The immediate effect of the threat may be an increase in risk assessments by shipping companies, insurers and cargo owners. European operators could face pressure to distance themselves from vessels that are owned, managed, insured or chartered through Russian-linked entities. Companies may also reassess routes through regions where Russian naval forces have a significant presence.
War-risk insurance premiums could rise if shipowners believe that commercial vessels may become targets in a sanctions dispute. Freight rates could also increase, particularly for tankers and bulk carriers travelling through routes perceived as vulnerable to naval interference.
The energy market could be affected as well. Russia depends heavily on maritime transport to sell oil to buyers outside the Western sanctions coalition. If European measures disrupt the shadow fleet, Moscow could face higher transport costs, fewer available tankers and greater dependence on non-Western maritime services.
However, retaliatory seizures could create costs for Russia too. A campaign against European vessels could trigger additional sanctions, lead to the detention of Russian-linked ships in other jurisdictions and increase the pressure on countries that continue to provide flags, insurance or port access to Russian operators.
The greatest risk is miscalculation. A boarding operation that begins as a regulatory inspection could become dangerous if a vessel refuses to cooperate, if armed personnel are present or if a navy attempts to intervene. Even without shots being fired, a prolonged detention could provoke diplomatic retaliation and disrupt international trade.
