Drone incidents at airports and military bases all over Jutland, western Denmark, have not caused any harm or damage - and yet they have exposed the country's defenses as vulnerable to attack.

In an era of hybrid warfare, there is a sense of embarrassment in Denmark - a founding member of the North Atlantic Treaty Organization (Nato) alliance - that its critical infrastructure has become so vulnerable.

Aalborg and Billund airports had to close on Wednesday night, while drones were spotted at Esbjerg, Sonderborg, and Skrydstrup. Aalborg also serves as a military base and Skrydstrup is home to some of the air force's F-35 and F-16 warplanes. Drones were also seen over the Jutland Dragoon regiment at Holstebro.

There have since been reports of police investigating drone activities around Denmark's oil and gas platforms in the North Sea, and near the central port of Korsor. Aalborg airport briefly closed again on Thursday night following another suspected drone sighting, police and national media said on Friday.

The question now facing the country's military is how to respond. None of the drones have been shot down - defense chiefs decided it was safer not to, but that is not a long-term solution. Denmark is, of course, not alone. Norway, Estonia, Poland, Bulgaria, and Romania have all experienced hybrid warfare in recent weeks.

Denmark has said a 'professional actor' was responsible for the drone attacks it saw, and left it at that. However, Frederiksen is in no doubt about the threat. Defence Minister Troels Lund Poulsen stated it looked 'systematic', referencing the number of targeted locations.

As investigations continue, Denmark is reassessing its defense strategies while joining NATO allies to explore measures to enhance air defense capabilities, including a proposed 'drone wall'. The situation serves as a wake-up call, forcing the Danish government and military to contemplate a new security reality.