“From an engineering perspective it’s so much easier to build a drone that can fly than to build something that can keep them from flying,” said Kjeld Jensen of the University of South Denmark. That blunt observation now defines a growing security dilemma for Denmark and its NATO allies, as unidentified drones have invaded airspace over the country’s largest military base and several airports in recent days.
On the late Friday night, police confirmed a sighting of one or two drones above and beyond the perimeter of Karup Air Base, which houses all Danish Armed Forces’ helicopters, airspace surveillance, and major command functions. The base shares facilities with Midtjylland Airport, which closed briefly but no civilian flights were planned at the time. The Danish Defence Command on Friday reported sighting drones at “several of the Danish Defense’s locations” overnight using undetailed equipment to observe the intrusions.
They came after a week of air disruptions that closed Aalborg Airport a military airport as such as well as Copenhagen Airport, Billund, and several small ones. Several of these overlapped with sighting reports of drones over Norway’s Ørland Air Base, home to its F-35 fighter jet fleet, and Germany’s Schleswig-Holstein border region along Denmark. Norwegian authorities reported at least two drones operated “about an hour” in closed airspace over Ørland that were not intercepted.
Danish Prime Minister Mette Frederiksen has called the incidents “the most serious attack on Danish critical infrastructure to date,” and as hybrid attacks missions that utilize both military and non-military instruments to destabilize a target. Defence Minister Troels Lund Poulsen called the flights “the work of a professional actor” and “systematic,” and at many locations almost simultaneously. Justice Minister Peter Hummelgaard added that the notion was “to spread fear, create division and frighten us.”
Though Russia has been in the limelight during speculations, the Danish government insists it has no hard evidence yet to indicate that Moscow is the country behind the crossing of borders. The trend, however, is mimicking hybrid warfare from other regions of Europe, including Russian drones intruding in Polish airspace and fighter jets intruding in Estonia’s airspace last month. Both Estonia and Poland responded by invoking NATO’s Article 4, which brings friends together when a member’s security has been compromised. Denmark has not yet invoked Article 4, Foreign Minister Lars Løkke Rasmussen said, and added that “there is no reason to do so now.”
The engineering problem is deep. Interception of small unmanned aerial vehicles needs layered defenses combining radar, electro-optical sensors, radio-frequency detection, and countermeasures of jamming or kinetic interceptors. Denmark’s present systems seem to be intended to deal with conventional threats and not low-altitude, low-speed drones potentially from nearby ships or concealed ground sites. Authorities have attempted to establish if drones came from ships in Danish waters, pointing to Russian-linked tankers like the Pushpa a part of a “shadow fleet” intended to evade sanctions off Aalborg for one assault.
NATO has committed to increasing watchfulness in the Baltic region with “multi-domain assets” such as intelligence, surveillance, and reconnaissance units and a single air-defense frigate. These steps continue the alliance’s existing “Baltic Sentry” mission with the deployment of patrol aircraft and naval drones for the protection of undersea cables, pipelines, and other infrastructure of vital importance. The just-established “Eastern Sentry” mission would extend defense along Europe’s eastern frontier against aerial attacks.
Regionally, the European Union is racing to deploy a “drone wall” along its eastern perimeter, taking cues from Ukraine’s battlefield anti-UAS defenses. EU Defence Commissioner Andrius Kubilius emphasized haste: We need to speed things up… taking all the lessons out of Ukraine and constructing this drone wall with the support of Ukraine. Sweden provided Denmark with its anti-drone capability prior to an EU summit in Copenhagen, highlighting the trend of continental integrated defenses.
Operational restraint is still part of Denmark’s policy. Defence head Michael Hyldgaard described how shooting down drones over populated or sensitive targets risks falling debris, fuel, or batteries. This is a show of restraint in comparison with Poland’s policy of immediate shooting down of incoming drones which, while destroying them, also results in collateral damage like the destruction of a house roof at Wyryki.
The attacks revealed vulnerabilities in NATO’s northern airspace, where it is challenging to repel small, locally based drones that can hide from conventional radar and take advantage of loopholes in the speed-of-response policies. For security-minded analysts, the Danish experience is a sobering reminder that in the early phase of the conflict between drone threats and counter-drone technologies, the point of advantage lies with the offense.
