UK shadow fleet boardings: pledge made, no action taken

Over 180 sanctioned shadow fleet vessels have transited British waters without a single recorded boarding since the UK government announced in March that its armed forces had the authority to intercept such ships, raising questions about whether unenforced commitments are undermining the broader Western sanctions effort.

Prime Minister Keir Starmer announced on 25 March that British armed forces and law enforcement could board and intercept sanctioned Russian shadow fleet vessels passing through UK waters, including the English Channel. Between 25 March and 11 May, 184 sanctioned vessels made 238 transits through those waters. No public evidence of a boarding has emerged.

When the question was raised at a CEPA press briefing on Tuesday, Mihkel Märtens, author of a new CEPA report on Russia sanctions, was careful not to comment directly on UK policy. But he confirmed the underlying principle without hesitation. “If you say you’re going to do something but then you don’t, that could lead to potentially an embarrassing situation,” he said. “Sanctioned vessels roam around everywhere, from Russian ports in the Baltic through to the Baltic Sea, the North Sea, the Mediterranean. The sanctions themselves can’t physically stop the vessels moving.”

Russia sanctions at a crossroads as US commitment wavers

The shadow fleet, experts at the briefing warned, poses threats well beyond sanctions evasion. Benjamin Schmitt, a senior fellow at CEPA and the University of Pennsylvania who recently testified before the US Senate Foreign Relations Committee, described the vessels as what he called “jack of all trade hybrid threats.” He told the briefing that French court proceedings involving the vessel known variously as the Kivalla, Pushpa, Borekai and Phoenix had produced testimony from a captain that unaccountable Russian security personnel from a group called Moran, allegedly including a former Wagner mercenary, were present on board, “collecting intelligence, monitoring the crew, monitoring the vessel, and doing God knows what else, unaccountable to the captain and crew.”

Schmitt, who said he personally observed the Kivalla being held under Estonian Navy interdiction in Muuga Bay in April 2025, and later helped identify the same vessel as a suspect in the shutdown of Copenhagen Airport through drone activity in September 2025, described the vessels as combining “sanctions evasion, possible sabotage, possible air incursions, possible espionage and signals intelligence, all of the above.”

The vessel, he noted, had since been renamed the Phoenix and was last seen sailing in East Asian waters toward Russia. “These vessels don’t disappear,” he said.

Schmitt was direct about the wider enforcement problem, arguing that the West needed a wartime level of staffing to match the scale of the task. “We can’t simply decide when sanctions are good for us,” he said. “It provides not only a permissive environment, but an environment in which the Russian Federation can start to strategise.”

The UK has sanctioned 544 shadow fleet vessels and remains an active participant in Joint Expeditionary Force discussions on coordinated interdiction.