Soldiers with the 5th Battalion, 4th Air Defense Artillery Regiment train on a Maneuver Short Range Air Defense system at Grafenwoehr Training Area, Germany, March 19, 2026. European air defenses are not equipped to deal with the drone threat, a new IISS report warned, after Russia likely used shadow fleet ships to launch drones that forced temporary airport closures and flew over NATO military installations across the continent. (Scyrrus Corregidor/U.S. Army)
STUTTGART, Germany — An extensive Russian drone campaign over Europe probed military bases housing U.S. nuclear weapons and other sensitive sites, exposing gaps in allied air defenses and an inadequate strategy to deal with the incursions, a new report said.
Between August 2024 and February 2026, hundreds of drones maneuvered in the airspace of a dozen NATO member states and Ireland, forcing repeated closures of major commercial aviation hubs and disrupting military activities, the International Institute for Strategic Studies said in a report issued Thursday.
Germany’s Ramstein Air Base, along with bases involved in NATO’s nuclear deterrence mission, was surveilled in an operation designed to map allied vulnerabilities and probe for weaknesses in military-civilian decision-making, the IISS report said.
Russia-linked ships, including vessels from its so-called “shadow fleet” of clandestine vessels, were used to launch drones as part of the Kremlin’s wider “unconventional war on Europe,” the report added.
During the campaign, drones flew with “substantial impunity across European airspace — representing both a series of tactical successes for the Kremlin and a strategic failure of allied air defense,” IISS said.
Russia has at various times denied involvement in the drone missions, including incursions reported in Denmark and Norway.
During the past two years, drone sightings have been reported across Europe. The threat became more urgent in September when NATO fighters shot down a swarm of drones headed into Poland. The incident marked the first time in history that NATO planes fired on potential threats in allied airspace.
In other cases, countries struggled to formulate a response to incursions. When they did respond, they failed to hit their targets, the IISS report said.
Between November 2024 and early 2025, drone flights occurred over Ramstein Air Base, according to IISS data culled from media reports and other open sources. It said the aircraft were likely launched from Russia-linked vessels operating as far away as the North Sea or Baltic Sea.
The IISS analysis also highlighted instances at various locations known to be connected to NATO’s nuclear mission.
Volkel Air Base in the Netherlands was targeted by drones on at least three separate days in November and December 2025, the report said.
“Volkel is a highly sensitive site because it hosts dual-capable aircraft tasked with delivering US forward-deployed B61-12 gravity bombs under NATO’s nuclear-sharing arrangements,” the report said.
Volkel is located deep inland. To reach it from the sea, drones would have had to bypass coastal naval dockyards and other air bases, demonstrating “a highly motivated and deliberate effort to survey NATO’s nuclear-deterrence infrastructure,” IISS said.
In one incursion, up to 10 drones were spotted directly over Volkel. Base security personnel fired ground-based weapons, but the drones evaded a direct hit and no wreckage was recovered, the report said.
European governments have responded to the Kremlin’s campaign “with neither unity nor consistency,” the report added.
NATO’s official position “compounded the incoherence,” IISS said.
Secretary-General Mark Rutte has stated that the alliance would not shoot down all drones as a matter of policy and would make decisions on a case-by-case basis. However, the lack of a unified approach has undermined NATO’s ability to project power, the report said.
The Kremlin’s tactical successes stem from a European air-defense architecture designed to detect and defeat conventional air threats, according to IISS.
“It was not developed for repeated, low-cost and deniable incursions with the aim of exposing gaps in detection, decision-making and legal authority while remaining below the threshold of collective allied response,” the report said.
Going forward, allies must develop a clearer legal framework to authorize advanced military assets against drones of uncertain origin moving over allied airspace, the report said.
“The path to a credible European response requires legal clarity,” the report said.
