Denmark Drone Incursions Expose EU Airspace Vulnerabilities

Prime Minister Mette Frederiksen urged Danes to prepare for more “hybrid attacks,” including sabotage and cyberwarfare, after drones repeatedly disrupted flights across the country. Prime Minister Mette Frederiksen urged Danes to prepare for more “hybrid attacks,” including sabotage and cyberwarfare, after drones repeatedly disrupted flights across the country.

Denmark is grappling with a new wave of suspected hostile drone activity that has grounded flights, shut down airports and exposed serious gaps in European airspace security. In less than a week, six airports—including major civilian hubs and military installations—were disrupted by unidentified unmanned aerial vehicles. The government has raised the alert level, with Prime Minister Mette Frederiksen warning that “Russia remains Europe’s main enemy” and calling the incidents part of a wider pattern of hybrid warfare. 

A string of airport shutdowns

On Thursday evening, Aalborg airport and its adjacent military base were forced to close for an hour due to suspected drone activity. Similar alerts earlier in the week affected Copenhagen’s main airport as well as Billund, Esbjerg, Sønderborg and Skrydstrup—installations critical to both civilian travel and military operations. While no drones were shot down, officials admitted they were seen at close proximity to aircraft filled with passengers and fuel, making interception too risky.

Defence Minister Troels Lund Poulsen confirmed that “two to three large drones” had been spotted near Copenhagen airport, calling the events a deliberate “hybrid attack.” He suggested they may have been launched from vessels in the Baltic Sea, underscoring the complexity of defending open skies and maritime borders.

The Danish opposition has sharply criticised the government for failing to anticipate such attacks. Alex Vanopslagh, leader of the Liberal Alliance, said: “It is both embarrassing and frightening. And the government owes it to Denmark to get this under control.” Others accused Copenhagen of ignoring lessons from Ukraine’s war, where Russia has repeatedly employed cheap drones to undermine far more expensive Western defence systems.

Military chiefs admitted they were ready to shoot down drones on Thursday but refrained after an “overall assessment” of risks. Critics argue the cautious approach has emboldened potential adversaries.

Russia blamed, but denies involvement

Although Danish authorities have not conclusively identified the perpetrators, Frederiksen pointed squarely at Moscow. “I note that there is one country that is the primary enemy of Europe. And that is Russia,” she said. Intelligence officials assessed the risk of Russian sabotage and espionage as “high,” noting the pattern resembled hybrid warfare seen in Ukraine and other NATO states. 

Moscow dismissed the accusations, denying involvement. Yet NATO and EU officials condemned Russia’s “reckless” behaviour in previous cases of drones and aircraft intruding into European airspace, including confirmed incursions into Poland, Romania and Estonia earlier this month.

A European response: the “drone wall”

The incidents in Denmark have accelerated continental discussions about a coordinated defence strategy. EU defence ministers from Denmark, Slovakia, Ukraine and other eastern flank states convened on Friday to explore building a “drone wall.” The concept envisions pooling anti-drone technology, early warning systems and air defence assets to shield Europe from hybrid attacks. NATO officials are also engaged in shaping the response.

Denmark is considering buying Ukrainian-developed technologies—ranging from acoustic sensors to cheap interceptor drones—that have proven effective against Russian attacks. “We cannot today present a solution that removes the threat from drones, but we will buy whatever is needed,” Poulsen said, adding that Ukraine’s battlefield innovations could serve as a model for Europe. 

Experts say the drone incursions highlight the difficulty of protecting critical national infrastructure. Douglas Barrie of the International Institute for Strategic Studies noted the sheer range of potential targets—from airports and energy sites to pipelines and hospitals. “It’s very easy to do, and very difficult to counter,” he said.

Europe’s current defensive posture relies heavily on costly systems—such as $500,000 missiles or fighter jets—against drones costing as little as $20,000. This mismatch, analysts warn, makes hybrid attacks a highly efficient way for adversaries to destabilise Europe.

Hybrid war on Europe’s doorstep

For Frederiksen, the incidents reflect a broader strategy by Moscow: “Russia is doing what it can on several different levels to destabilise Europe—you do that with war directly, and you do it with hybrid attacks. And it has the same purpose, namely to shake the foundations of Europe.” 

The coming weeks will test whether Denmark and its allies can strengthen air defences fast enough to deter further incursions or whether Europe’s skies remain vulnerable to the next wave of hybrid warfare.