Western navies invoke UNCLOS to board Russian shadow tankers amid oil sanctions

Western sanctions prohibit the purchase of Russian oil and ban Western-insured tankers from reselling it, pushing Russia to rely on a shadow fleet of vessels with dubious registries. For the first time this year, the United States, United Kingdom and EU have invoked Article 110 of UNCLOS to board and inspect those ships, a practice previously limited to safety checks. The inspections have exposed illegal practices such as false flags, turned-off trackers and on-the-high-sea oil transfers, reducing Russia's ability to hide oil origins.

Flag states like St Kitts and Nevis and Palau have begun removing shadow tankers, while Russia has shifted many to its own registry, now listing hundreds of Russian-flagged vessels. Denmark and Sweden have tightened checks in the Baltic Strait, a key chokepoint for Russian exports, though they stop short of closing the passage. The increased legal pressure aims to make it costlier for Russia to fund its war in Ukraine.