Danish drone incursion raises questions of Russian involvement as NATO strengthens eastern defenses

A drone incursion over Denmark forced Copenhagen’s Kastrup Airport to shut briefly Monday night, in what Prime Minister Mette Frederiksen called the most severe attack on Danish infrastructure to date. The closure began around 20:30 local time and lasted for several hours, leaving roughly 20,000 passengers stranded or rerouted as the airport resumed operations after midnight. Authorities have cautioned that the motive may have been to disrupt rather than to cause direct damage.

Frederiksen, who linked the Copenhagen event to recent Russian drone incursions in Poland and Romania—and to a violation of Estonian airspace by Russian fighters—said Russian involvement could not be ruled out. Kremlin spokesman Dmitry Peskov dismissed the allegations as unfounded. The Danish leader described the incident as a signal of the turbulent times and what society must be prepared to handle, and she said the likely aim was to test limits and sow unrest.

Danish intelligence echoed the severity of the threat, with PET director Flemming Drejer saying the country faced a "high threat of sabotage". Police described the drones as coming from several directions at a considerable distance and being operated by a group with the intent to showcase capability. Inspector Jens Jespersen said the devices turned their lights on and off as they approached the airport and that investigators believed the operators had the means and willingness to provoke attention. Police chose not to shoot down the drones because the airport sits in a densely built-up area and commercial aircraft were in the air at the time.

The episode echoed a broader pattern of Russian activity in Europe. Zelensky noted on social media that it amounted to a violation of NATO airspace in Copenhagen on Sept. 22, a claim Insp Jespersen refused to confirm, saying he did not know whether Zelensky’s post was accurate. In Oslo, an unconfirmed drone sighting prompted the closure of Oslo Airport for several hours, with 14 flights diverted. The Norwegian Police Security Service is assessing whether the Oslo sighting is connected to the Danish incident. Norway’s government has also noted that Russia has violated Norwegian airspace three times in 2025—in April, July and August—though investigators have not concluded whether those incidents were deliberate or navigational errors, a distinction that ongoing inquiries have not resolved.

The Danish episode occurred amid rising tensions as Russian drones and aircraft have appeared in central and eastern European airspace over the past year. In September, Russian drones were shot down by Polish and other NATO aircraft after violating Polish airspace, and a drone breached Romanian airspace shortly thereafter before vanishing from radar. Earlier this week, three Russian MiG-31 fighter jets briefly entered Estonian skies, triggering scrambled NATO jets. NATO said the incidents form part of a wider pattern of increasingly irresponsible Russian behavior.

In response to these incursions, NATO has pledged to reposition troops and fighter jets eastward to bolster the alliance’s eastern flank. Britain, France, Germany and Denmark have contributed aircraft and personnel to air-defense missions over Poland as part of the effort to deter further Russian activity. The mobilization comes as European governments seek to deter escalation and reassure allies near Russia, amid ongoing tensions over Moscow’s invasion of Ukraine. Officially, NATO has stressed that it is focused on deterrence and defense, with no evidence of any NATO member being targeted directly by Russian actions.