Russia likely employed shadow ships to launch drones across Europe, a tactic that repeatedly disrupted civilian aviation and tested the air defenses of NATO nations, according to a report from the International Institute for Strategic Studies (IISS). The report, which was shared with The Associated Press, documented 144 suspected drone sightings in NATO member states including Germany, France, Belgium, the Netherlands, the U.K., and Denmark between 2024 and 2026.

The incidents, which peaked in late 2025, led to the temporary closure of several European airports. Danish Prime Minister Mette Frederiksen characterized the incursions in her country as the "most serious attack on Danish critical infrastructure to date."

The IISS concluded that the Russian campaign was designed to avoid triggering a collective NATO response, labeling it a "strategic failure" for Europe that highlighted deficiencies in the continent's air defense capabilities. Air Chief Marshal John Stringer, NATO's deputy supreme allied commander in Europe, noted that while it is up to individual alliance members to determine their response, many are taking such threats with increasing seriousness.

Though attributing the incursions directly to Russia proved difficult for many senior European officials, Stringer suggested the activity aligns with patterns of disruption blamed on Russia since its 2022 invasion of Ukraine. Sweden is among the few countries to have directly attributed drone sightings to Moscow, citing an incident involving a military drone launched from a Russian spy ship near a French aircraft carrier.

Drones pose a unique challenge to detection due to their low and slow flight profiles, often appearing on radar as birds or planes. Their ability to be launched near or within national borders allows them to bypass traditional missile defense systems designed for long-range threats. Furthermore, identifying the origin and perpetrator of downed drones is exceedingly difficult.

The IISS report specifically examined drone sightings in central and northwest Europe, noting a correlation with the movement of Russian shadow fleet vessels—ships of uncertain ownership used to circumvent sanctions. The report suggested these vessels likely served as drone launch platforms.

Notable incidents detailed in the report include:

  • On January 3, 2025, up to 20 drones were observed flying over the port of Koege, Denmark, as a shadow fleet vessel sailed along the coast.
  • On September 22, 2025, drone sightings forced the closure of Copenhagen Airport while several shadow ships were in the vicinity.
  • The French military boarded the vessel Boracay at the end of September 2025, following drone sightings over Denmark. President Emmanuel Macron stated that the vessel's involvement in the drone flights could not be ruled out.

Denmark's Defense Command confirmed drone activity in its airspace in September and October 2025, noting that Moscow engages in hybrid attacks against the West that have escalated significantly since the war in Ukraine began.

The report also indicated that Russia may have attempted to monitor military sites in the U.K., Netherlands, Belgium, France, and Germany. These incursions may have been intended to provoke NATO responses, thereby revealing radar positions and defensive gaps. Sightings over military installations include:

  • Multiple drone sightings over four American air bases in the U.K. in November 2024, reported by the U.S. Air Force in Europe.
  • Over 1,000 suspicious drone sightings recorded by German authorities in 2025, including over defense companies and military bases.
  • Drones observed over military bases in the Netherlands and Belgium in November and December 2025, according to Dutch and Belgian defense officials. The IISS suggested these bases may host American nuclear weapons.
  • Drone sightings were also reported at the Ile Longue submarine base in France, which houses the country's nuclear-powered ballistic missile submarines.

Official responses to these specific incidents have varied. The U.S. Air Force in Europe stated it could not provide further details on the U.K., Netherlands, and Belgium incidents. A British defense official indicated that an investigation found no conclusive evidence linking U.K. drone sightings to Russia. The Dutch Defense Ministry confirmed drone sightings over Volkel Air Base and stated protective measures were enhanced. Investigations into drones over Ile Longue are ongoing, with the French army chief of staff headquarters not commenting on potential links to shadow fleet ships.

Lt. Gen. Jonny Lindfors, Sweden's military representative to NATO, suggested that given the frequency of incursions, it would be "naive to believe it's just a coincidence," implying that such threats are becoming a persistent challenge.