On the night of September 22, 2025, “the most serious attack on Danish critical infrastructure” unfolded
at Copenhagen Airport (Harper, Jon. “A drone fly-over above Copenhagen Airport prompts concerns that Russia was behind it.” AP News, 22 Sept. 2025). What the Danish Prime Minister described was not a terrorist hijacking, a crippling cyber attack, or an enemy fighter jet overhead. Rather, it was two or three commercially available drones – the same ones that hobbyists buy online every day.
The small intruders caused massive disruptions, forcing pilots to divert and airlines to cancel flights as the airport shut down for several hours.
While no damage occurred, the incident was yet another in a growing pattern of drone incursions targeting critical sites. To date, thousands of drone detections have plagued European airports, government facilities, and military bases over the past couple of years. Similar events have been reported in the United States, as well (Stein, Aaron, and Tim Ball. “Small Drones, Big Problems: Managing the Unmanned Threat to the Homeland.” Foreign Policy Research Institute, 2 Sept. 2025).
The consequences of waiting to act have already been shown. When a Saudi oil field was attacked by Houthi drones in 2019, global supply lines were choked and hundreds of millions of dollars were lost in the aftermath (Rasmi, Adam. “The oil field attacks could cost Saudi Arabia hundreds of millions of dollars per day.” Quartz, September 14, 2025). More recently in 2024, a single fixed-wing UAV launched by Hezbollah from southern Lebanon flew dozens of kilometers deep into central Israel; despite being tracked by radar and Israeli Apache helicopters, they were unable to down the drone due to the risk of harming civilians on the ground. The drone eventually reached its intended target, and recorded a direct hit on the personal residence of the Prime Minister. It is only a matter of time before drone detections above European capitals and US sensitive sites become full-blown drone attacks on critical infrastructure. The immediate need to secure critical infrastructure remains urgent, both against harmless commercial drones and advanced UAVs.
Saudi Aramco Fuel Depot Hit by Houthi Drone Attack
Source: Bloomberg
Operation “Spider Web” Ukraine
Whether lone suspects or a group of hackers, contemporary thinking around security has always placed people as the most dangerous threat. Someone trying to enter, steal, or sabotage was the focus of critical site defense. That’s why most site security consists of 4 main elements: physical barriers like fences, active armed/unarmed guards, CCTV mainframes, and cybersecurity frameworks. However, while human threats remain, drones are quickly becoming an even greater risk. Their agility, maneuverability, and advanced video feeds bypass walls, cameras, and access control entirely – all without exposing the pilot. Add in their cheap production price and small warhead, and suddenly a ~$1,000 UAV can cause millions of dollars in damages depending on their target. With their low prices and low profiles, drones have become the ultimate asymmetric tool.
Governments and militaries are well aware of the UAS threat, and have begun deploying countermeasures at key strategic sites in order to combat increasing drone activity. According to Archive Market Research, the global market for airport C-UAS systems is valued at roughly $800 million alone, and is growing at about 15% annually (“C-UAS Systems for Airports: Decade-Long Trends, Analysis and Forecast 2025-2033.” Archive Market Research, 5 Jul. 2025). Investments in classified military programs and critical infrastructure protection are likely far higher. In fact, the US military reported more than 350 drone detections across 100 different installations in 2024 (Harper, Jon. “NORAD Commander Says Hundreds of Drone Incursions Were Detected at US Military Installations.” DefenseScoop, 13 Feb. 2025.). Yet, despite this growing awareness and investment, significant challenges remain in deploying effective C-UAS arrays around fixed and urban sites.
Israeli PM’s Private residences after a Hezbollah suicide drone attacK
First of all, many critical sites, whether government buildings or airports, are embedded within civilian infrastructure. This requires regulatory and operational flexibility, especially in the important “response” stage of threat mitigation. Global regulations are strict in terms of the use of direct-effect response mechanisms in populated areas, such as explosive interceptors or aerial shoot-downs. The risk to uninvolved civilians below is simply too high. As a result, many critical sites rely primarily on electronic warfare (EW)—detection, jamming, and command-and-control—to mitigate drone threats. While effective, EW cannot stop drones using fiber-optic links (see previous article), and dense urban environments degrade jamming due to signal interference and physical obstructions. UAVs with GNSS-denied navigation systems also pose new challenges. Integration presents another obstacle: systems from multiple vendors require calibration, false-positive testing, and interface alignment to achieve seamless operation.
To overcome these challenges, stationary sites need an additional, integrated layer of C-UAS defense. Namely, a solution that enhances existing systems through seamless consolidation, complies with safety regulations, and bridges operational gaps. The DefendAir system offers a simple yet effective answer to contemporary demands, using advanced net-based interception technology. The technology is non-explosive and non-lethal, allowing for system deployment in urban environments, without risk of collateral damage. Furthermore, the DefendAir can be integrated into existing detection and EW frameworks, bolstering current defense umbrellas while adding a final layer of C-UAS defense.
Drone technology will only continue to advance, and the defense of critical infrastructure, from international airports to military bases to power plants, must be ready to confront the next UAV threat. From hobbyists accidentally flying a drone into restricted airspace to enemies of the state testing current defenses, each drone incursion must be dealt with uniformly and decisively. Tomorrow’s drone threat is already here. Is your defense ready?
