A report by the International Institute for Strategic Studies (IISS) in London has concluded that Russia orchestrated an 18-month drone surveillance campaign targeting nuclear and military installations across Europe, operating with what the institute describes as “substantial impunity.” The analysis, which examined 144 incidents between August 2024 and February 2026, found that unmanned aerial vehicles were repeatedly sighted over sensitive sites—including air bases hosting US nuclear weapons in Belgium and the Netherlands, the French nuclear submarine base at Île Longue, and Royal Air Force stations in Britain—yet none were intercepted or shot down by NATO forces. The IISS assesses that the drones were launched from commercial vessels, notably tankers belonging to Russia’s “shadow fleet” used to circumvent oil sanctions.

The Kremlin has dismissed the allegations as unfounded, with a spokesman describing them as “groundless.” Western governments have offered varied responses. According to the report, French special forces boarded a shadow tanker, the Boracay, in 2025 on suspicion of drone launches but did not publicly disclose their findings; the vessel was later released. Danish and Norwegian authorities, whose airports were disrupted by drone sightings, have stated they lack conclusive evidence of Russian involvement. The IISS, however, points to a pattern of vessel movements correlating with incursions: the cargo ship Hav Dolphin was near the UK coast during drone flights over US bases in November 2024, and the same vessel was later in the vicinity of a German submarine base when drones appeared there in May 2025. The report notes that some ships likely functioned as relay platforms, with one vessel launching and recovering drones while another provided communications support.

Analysts in London argue that the campaign exposed a strategic vulnerability in NATO’s air defence architecture, which is designed to counter conventional aircraft and missiles rather than small, slow-moving drones operating at low altitude. European defence officials, speaking on condition of anonymity, have acknowledged that rules of engagement and legal constraints on the use of force against drones in peacetime airspace limited their ability to respond. The IISS report states that the operation “represented a series of tactical successes for the Kremlin and a strategic failure for allied air defence.” The European Parliament has previously noted that a NATO mutual defence programme against drones, launched after incursions into Polish airspace in September 2025, lacked the agility and doctrinal coherence to deliver results.

The drone campaign is viewed by Western security services as part of a broader unconventional conflict waged by Moscow against European states, which has included sabotage, arson, and cyber attacks. In February 2026, Sweden electronically intercepted a drone approaching the French nuclear-powered aircraft carrier Charles de Gaulle in the Baltic Sea; an investigation traced the device to a Russian spy ship, the Jigulevsk. Since then, European navies have begun seizing shadow fleet vessels, and the IISS notes that drone sightings have declined. The dossier remains open: no collective NATO response has been announced, but the report’s publication is expected to intensify pressure on allied governments to close the identified gaps in airspace surveillance and rules of engagement.