Hybrid Warfare Escalates as Drones Target Denmark's Infrastructure

Denmark reported coordinated drone sightings near critical infrastructure and military facilities on September 24–25, 2025, prompting the closure of Aalborg Airport and placing three other airports on high alert. The incidents, described as a "hybrid attack" by Danish officials, involved unauthorized drones flying near airports and military installations, including Skrydstrup Air Base and the Jutland Dragoon regiment. Authorities authorized the use of military force to shoot down drones in future incidents but ruled out immediate action near civilian airports due to safety concerns.

Defense Minister Troels Lund Poulsen emphasized the professionalism of the operation, noting it involved "systematic" execution by actors with technical expertise. While no direct evidence has linked the attacks to a specific country, speculation points to potential Russian involvement, given similar incidents at Copenhagen and Oslo airports and broader airspace violations by Russian drones in NATO territories. Denmark’s intelligence chief, Finn Borch, warned of a high risk of Russian sabotage but stopped short of naming a culprit.

NATO issued a strong condemnation of Russia’s recent airspace violations, including incursions in Poland, Romania, and Estonia, and warned of escalated defensive measures. The alliance’s Secretary General, Mark Rutte, stated, “We are a defensive alliance, yes, but we are not naive,” underscoring readiness to use “all necessary military and non-military tools” to counter threats. Denmark is considering invoking NATO’s Article 4 protocol, which allows consultations when a member’s security is threatened, though no formal request has been made yet.

The drone incidents follow a pattern of hybrid warfare tactics, including cyberattacks and propaganda, aimed at destabilizing European security. Analysts suggest such operations seek to create fear, disrupt critical infrastructure, and test NATO’s response mechanisms. Edward Arnold of the Royal United Services Institute noted, “Drone technology has become very sophisticated… this isn’t now the preserve of elite, state-based actors,” highlighting the growing accessibility of high-tech drones.

Denmark’s defense capabilities remain limited in addressing the current threat. The country lacks a ground-based air defense system and acknowledged its existing tools are insufficient to counter advanced drones. Lund Poulsen confirmed plans to purchase such systems but emphasized a multifaceted approach, including drone jamming and counter-drone technologies, to mitigate future risks. The European Commission has also raised alarms, with President Ursula von der Leyen labeling the attacks part of a broader pattern of “persistent contestation at our borders”.

The incidents underscore heightened tensions in Europe as NATO members grapple with hybrid threats. Similar drone disruptions in Norway and Poland have reinforced concerns about coordinated efforts to exploit vulnerabilities in air defense systems. While Denmark and its allies have yet to confirm a direct link between the recent attacks, the timing and methods suggest a strategic intent to escalate regional instability.

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