By: Alexander MacDonald and Francesco Milner
Wall in the Sky
Thirty-five years after the fall of the Berlin Wall, Europe is building another kind of barrier. This one isn’t made of stone and steel, but of sensors, signals, and electronic defences. From Poland to Denmark, unidentified drone incursions widely attributed to Russia have forced airport closures, triggered radar alerts, and set off national security investigations. On 10 September 2025, around twenty Russian drones breached Poland’s airspace, forcing NATO jets to scramble; similar violations occurred there in October, when Dutch F-35s were deployed to intercept additional Russian drones. Countering thousand-dollar drones with multi-million-dollar aircraft and missiles has highlighted a stark cost imbalance, pushing European leaders to accelerate plans for a ‘drone wall’: a conceptual sky shield meant to detect, disrupt, and, if necessary, destroy anything that enters European airspace. Comprised of radars, sensors, electronic jammers, and precision interceptors, this layered network is meant to spot, confuse, and neutralise illicit drones. The urgency is growing, as commercially-available Unmanned Aerial Systems (UAS) have evolved far beyond recreational gadgets, offering clear dual-use potential. Such UAS can appear unpredictably, evade conventional defences, and leave critical infrastructure highly vulnerable.
A Continent Under Intrusion
A recent paper analysing Russia’s unconventional war on Europe from the International Institute for Strategic Studies argues that recent drone incursions are not random violations but part of a broader strategy to probe NATO’s air-defence limits. This strategy became evident from September 2025, when Poland faced more than twenty unauthorised drones breaching its skies, forcing the temporary closure of major airports. Romania scrambled aircrafts after violations near its borders, whilst Denmark shut down airspace around Copenhagen and Aalborg following drone sightings near civilian and military sites. The pattern extended into October and November, when airports in Belgium, Germany, Norway, and Spain also reported incursions and disruptions. These incidents taken together illustrate how dispersed, low-cost technology can undermine even advanced defence systems, turning the continent’s skies into a new and unpredictable frontier of vulnerability, forcing governments to rethink how they protect their skies.
Yet a critical question remains: whose drones are these? Although official statements often avoid explicit attribution, the overwhelming consensus across European intelligence and defence communities, as well as independent investigations, is that these incursions are part of Russia’s ongoing grey-zone campaign against Europe. While not every incident can be conclusively traced to Moscow, the consistency of flight patterns, targeting choices, and timing strongly aligns with known Russian hybrid tactics, whether executed directly or through affiliated operators. Recognising this attribution matters because ignoring it risks presenting these incursions as random or mechanistic, rather than as deliberate probes designed to test response times, map vulnerabilities, and impose operational or financial strain. Understanding Russia’s motivations and strategic logic behind deploying low-cost drones to unsettle European airspace is now central to shaping a credible defensive posture.
The Technological Arms Race
Drones have come to occupy a key role in modern armed conflict, proving their value as comparatively low-cost, highly-versatile platforms capable of generating significant effects on the battlefield without directly endangering one’s own soldiers. In response, the global market countering Unmanned Aerial Systems (UAS) has boomed. It is projected to surge to around €5 billion by 2029, with both drones and anti-drone systems forced to evolve in a mutual cycle of innovation.
One of the most effective ways to counter drones is by exploiting the electromagnetic spectrum, especially through jamming. To be effective, a jamming signal must overpower the drone’s own control signal by transmitting sufficiently robust interference. However, jammers can be limited by range, with smaller emitters reaching only about 3 kilometres. Larger systems, with ranges of about 80km, face logistical challenges in supplying enough power and maintaining proper cooling. Experience from Ukraine has shown that a hybrid approach has proven most effective, with a layered defence architecture consisting of small, highly mobile jamming teams and pre-positioned modular generators, paired with powerful but static larger installations.
Electronic warfare in the form of directed-energy weapons, such as lasers and high-powered microwaves, is also being increasingly developed for deployment in a future ‘drone wall’. Whilst the initial cost of producing these systems is high, they benefit from a relatively low cost-per-shot when compared to traditional anti-aircraft missiles. This helps reduce the unfavourable cost curve of C-UAS warfare, which has often pitted €30,000 attack drones against missiles or fighter jets costing 10 times as much.
However, drones are also advancing to address these directed-energy threats through material hardening, with prototypes under development featuring ceramic shielding that would allow the drone’s body to absorb or deflect directed energy away from critical electronics. Furthermore, some UAS have started utilising fibre-optic communications, which are immune to jamming. These UAS are deployed towing elongated fibre-optic cables back to their bases, becoming ‘militarised kites’ capable of ranging up to 20 miles.
Tactical Evolution
Technology is not only producing more advanced drones but also transforming how they are employed tactically, creating significant challenges for constructing a viable ‘drone wall’. In Ukraine, the armed forces have compiled a vast dataset of over 2 million hours of drone footage from more than 15,000 frontline units, feeding AI systems that assist with automated target identification, battle damage assessment, and optimised flight planning. These enhancements allow operators to react faster, fly smarter, and strike from different angles. As a result, Ukrainian battlefield expertise is now being directly integrated into European defence planning, translating combat-tested drone tactics into practical lessons for continental air defence.
Further developments, such as drone swarms and decoy drones, are expected to further complicate defence. By saturating the battlespace with both real and fake targets, swarms can swamp sensors and operators, creating information overload and rapidly draining a defender’s ammunition. These innovations have already appeared in high-profile operations; Ukraine’s 2025 Operation Spiderweb used UAS launched from deep inside Russian territory, deployed from mobile trucks and guided by semi-autonomous AI systems. Similar tactics were used in Israel’s Operation Rising Lion, which leveraged unconventional vectors of attack to blind Iranian air defences and clear a path for more vulnerable air assets.
Burden-sharing and Low-Tech Solutions
Constructing a meaningful and effective drone wall faces significant geopolitical and policy implications for Europe. The very notion of a ‘wall’ in which defences can be concentrated across a frontier zone facing East is problematic. This is due to unpredictable flight paths, mobile launch sites, including ships, and the potential for dual-use components to be smuggled across borders and then used to 3D-print drones launched within allied territory. Which countries should then be considered most threatened by these incursions, and who should shoulder what proportion of the cost for any ‘drone wall’, remains an unresolved question. A central policy challenge: the widening cost asymmetry between offensive drones and defensive countermeasures, will only exacerbate this issue within NATO, which is increasingly challenged by populism and a desire of members to balance national self-interest alongside collective defence obligations. Meanwhile, adversaries can continue to deploy large volumes of cheap drones or decoys at minimal cost, exacting a high policy price tag.
A potential path forward is to pursue low-tech defensive tools that can be cheaply mass-produced. Observations from Ukraine could inspire such solutions, where Sweden has donated old fishing nets that now line roads and cover command posts, providing a rudimentary but effective physical barrier against kamikaze drone attacks. Similarly, tools such as anti-aircraft flak, heavy machine guns, snipers, man-portable shoulder-launched systems, or even shotguns are unsophisticated but often potent counters to UASs, which are already in abundant supply in the arsenals of most European militaries. Drone-on-drone engagements observed over Ukraine have shown rudimentary solutions in ramming-style dogfights using tree branches attached onto drone bodies, to bludgeon hostile intruders out of the sky.
Conclusion
Ultimately, the construction of a successful ‘drone wall’ will depend on more than acquiring new technologies. It will require coherent policy choices, realistic procurement timelines, and a shared understanding among NATO members of what such a system can and cannot deliver. This calls for a ‘drone wall’ that is layered, offers 360-degree coverage, and is integrated into NATO force structure. The balance between low-tech resilience and high-tech precision is key, shaping Europe’s ability to sustain defence operations during a protracted crisis. Lessons from Ukraine show that counter-drone strategies must evolve at the pace of the threat: drones are becoming cheaper, faster, and more autonomous, while existing defences remain costly and complex.
In this context, Europe’s challenge is not simply to build a drone wall, but to construct one that is politically sustainable, financially viable, and resilient to attacks from across the full spectrum of approach vectors. This means complementing advanced systems with inexpensive, widely deployable defences that can be rapidly fielded across NATO’s eastern flank. Europe may aspire to build the ‘Iron Curtain of the skies,’ but its success will hinge on whether it can combine technological ambition with strategic pragmatism and do so before the threat grows faster than its ability to respond.
Edited by: Arturo Simone and Jekaterina Savicka
Image Source: C-RAM system firing at Kandahar Airfield at night during a test response to
indirect fire attacks. Photo by Staff Sgt. Sean Martin, U.S. Air Force (public domain)