In late November 2024, unidentified drones flew over RAF Lakenheath, RAF Mildenhall, RAF Feltwell and RAF Fairford, bases in England used by the U.S. Air Force. Lakenheath was being prepared to host American nuclear weapons, which arrived in July 2025. More drone sightings followed across Europe, including over Dutch and Belgian air bases believed to store U.S. nuclear bombs and France’s Île Longue nuclear submarine base. None of the drones was shot down or captured.

On July 2, 2026, the International Institute for Strategic Studies, a London think tank, published an analysis of 144 incidents across 13 countries between August 2024 and February 2026. It concluded it was highly likely that Russia had used ships from its shadow fleet, the aging tankers it uses to move oil around sanctions, as platforms to launch and recover drones. In each case, it said, one or more such vessels had been nearby. It named the HAV Dolphin and the Seasons I as being off the English coast during the Lakenheath flights, and suggested Russia’s GRU military intelligence was behind the campaign.

Critics pushed back. The Dutch monitoring group Dronewatch said the report rests largely on timing coincidences and includes sightings already explained, including a Lakenheath incident later attributed to a U.S. F-15 and a Belgian one that was a police helicopter. Danish police said in June that inspected shadow-fleet vessels, including the two named, had no connection to drone sightings. A British Ministry of Defence inquiry into Lakenheath identified no suspects.