A report from the International Institute of Strategic Studies (IISS) indicates that Russia is using a fleet of older ships, referred to as a shadow fleet, to launch drones at European military bases and airports. This activity appears aimed at assessing the response times and air defenses of NATO allies. The report notes that between August 2024 and February 2026, 144 suspected drone incidents were recorded near military and nuclear sites in Germany, France, Belgium, the Netherlands, the UK, and Denmark, as well as over American air bases in the UK in November 2024.
Retired Lt. Gen. Ben Hodges, former commanding general of US Army Europe, stated that the shadow fleet is being used to bring various types of drones closer to European countries. In Germany alone, there were over 1,000 suspicious drone sightings in 2025, particularly over defense companies and military bases where Ukrainian soldiers were training.
Elisabeth Braw from the Atlantic Council suggested that these drone activities are testing not only the authorities' reactions but also public responses to potential crises. The report highlights that these drone incursions have disrupted major commercial aviation operations and penetrated sensitive defense installations.
The IISS report also notes that the drone campaign is designed to probe the decision-making processes of allied air defense and civil-military command structures, identify vulnerabilities in critical infrastructure, and impose psychological and economic costs on European societies. The sightings peaked in late 2025, leading to temporary airport closures in several European countries.
Sweden has directly accused Moscow after a drone launched from a Russian ship approached a French aircraft carrier. Russian President Vladimir Putin has denied allegations of sabotage and surveillance, questioning the validity of the claims. The IISS tracked the movements of Russia's shadow fleet and linked them to drone incidents, suggesting that these ships provide a platform for launching drones while maintaining plausible deniability. Additionally, unauthorized drone sightings have also been reported in the U.S., prompting investigations by military authorities.