Ukraine’s overnight drone strike on Russia’s territory on 22-23 September may have contained something unprecedented — high-flying balloons, possibly armed with explosives of some kind.

Russian officials reported shooting down dozens of drones, but the Russian Ministry of Defense made no mention of balloons — or aerostats, per the more technical terminology.

The reports of aerostats drifting over Russia largely came from Russian Telegram channels, which warned of balloons containing explosive objects of unspecified nature.

Russian publication RBK cited unnamed Russian defense officials in claiming that a large number of balloons was observed during the attack, something they hadn’t previously seen Ukraine throw at them.

One Russian channel reported a balloon flying at an altitude of 10 kilometers, which is a typical cruising altitude for commercial airliners.

The attack reportedly forced flights to divert from Moscow’s Sheremetyevo airport.

Fixed-wing drones were reportedly sighted over Moscow during the attack, matching the profile of the UJ-22 Airborne bomber UAVs in use by Ukrainian forces.

Does Ukraine’s military use balloons as weapons?

While Ukraine made no mention of technology used in the strike, the country’s armed forces have access to tethered balloons that can serve as detectors and launch platforms for interceptor UAVs to strike down Russian attack drones.

Pictures from social media in March appear to show a balloon developed by the Ukrainian company Aero Bavovna carrying a fixed-wing drone under its translucent belly.

On its website, Aero Bavovna describes its aerostats as “accessible and versatile airborne platforms for communication and monitoring” that can provide “reliable control and security in any conditions for both mobile and stationary applications.”

The company says balloons can carry payloads including FPV repeaters, communicators, cameras, and electronic countermeasures, although it makes no mention of launch cradles for smaller drones.

In a recent interview with Euromaidan Press, Hudson Institute fellow Brigham McCown mentioned that tethered aerostatic drones can be useful devices for monitoring and detection thanks to their indefinite uptime.

The multi-kilometer heights balloons can reach may also put them out of range of many shorter-range countermeasures.

European officials went scrambling for solutions after Russian drones violated Polish and Romanian airspace on 10 September.

The incident seemed to remind EU allies that their modern jets and fancy missiles may not be up to the task of fighting the cheap, massed drone swarms of the modern air war.

The proposed solution is a “drone wall” defense initiative, with support from the world’s foremost expert on drone warfare, Ukraine.

No one knows how such a project would look, how much it could cost, or when it might be ready. Estonia, Latvia, Lithuania, Poland, Finland, Romania, Denmark, and Bulgaria will meet with the European Commission and Ukraine on 26 September to discuss the initiative. The EU hopes to have a roadmap by late October.

Would the “drone wall” actually be a wall?

While “drone wall” is a striking name, some defense experts who spoke with Euromaidan Press said it may not be the best metaphor for visualizing how such a system might look in practice.

An effective anti-drone system would look much more like a dense, interconnected network of multiple overlapping layers of detection and interception. No layer will be fully effective by itself. Some layers may have to be switched out entirely over time, as new enemy threats render them obsolete.

“It is undisputed that defending against cost-effective long-range drones using fighter aircraft… or using expensive missiles fired from highly complex ground-based air defense systems, are not sustainable approaches,” German military expert Waldemar Geiger wrote for Hartpunkt.

However, “while a single interception attempt with (cheaper drone-based) systems may be cost-effective, establishing a comprehensive drone defense system is and remains very expensive.”

If EU countries hope to preserve both cost and operational effectiveness, they need to approach the problem with boldness and a great deal of political will, experts told Euromaidan Press.

What makes drone detection so difficult

Timely and comprehensive detection of hostile targets is a prerequisite for all other solutions. If the allies can’t see the target, they cannot shoot it down.

The first layer is intelligence, collected from space, the air, and the ground. In Ukraine, foreign intelligence sharing has repeatedly given defenders early warnings when Russia was about to launch missile and drone barrages, by tracking vehicle and supply movements within both Russian and occupied territory.

On the operational and strategic levels, both Ukraine and Russia are expanding the use of signals intelligence to locate drones in space, so that kinetic systems or other mobile UAV units can be launched against them, said Samuel Bendett, a Russia studies adviser with the American think tank CNA.

While radar is part of a well-rounded detection system, long-range strike drones from the Shahed lineage have been known to dodge conventional radar.

Ukraine has made effective use of acoustic sensors that can detect the characteristic whine of Russian strike drones’ engines, with the Zvook project dazzling NATO officials.

Other detection systems can include passive radar and low-emission 3D radar tuned to detect remote-controlled objects.

Airborne radar, also mounted on drones, is a critical part of the equation. Both attackers and defenders rely on intelligence, surveillance, and reconnaissance (ISR) machines during operations involving drones.

Bendett added that Ukraine has gotten good at knocking down Russian ISR units with FPV drones.

However, Russia has also evolved. The Rubicon Center of Advanced Unmanned Technologies has been a leading force in Russia’s drone war since 2024, systematically working on ways to strip away Ukraine’s strength in drones, layer by layer.

Rubicon units specialize in different tasks, such as countering Ukraine’s FPVs or hunting its reconnaissance units, which have been hit especially hard, according to the 5 September episode of Ukraine’s Dronefall podcast.

“From the point of view of using reconnaissance units, we see what the enemy is doing and we need to, at least, do the same thing,” Valentyn Prokopchenko, the head of air defense for Ukraine’s Khartia Brigade, said on the podcast. “Naturally, more reconnaissance aircraft are needed because there won’t be a situation where there are no losses.”

Why electronic jamming isn’t enough

Electronic countermeasures, which disrupt UAVs’ command and control, form yet another — some might say iffier — layer of defense for Europe.

Electronic jamming is easier to bring to bear against tactical drones in Ukrainian battlefields, but becomes progressively more expensive in deployment and power requirements when trying to target operational and strategic-level weapons.

Attackers constantly adapt to overcome electronic countermeasures, but fiber-optic drones are impervious to this disruption.

Ukraine’s Defender Media outlet reported that Russians are testing the use of radio-controlled and fiber-optic drones in tandem.

Bendett said attackers can use “frequency hopping” — switching command and control channels to reduce the chance of being detected or disrupted. Electronic warfare is not always effective against Shahed-type machines, he added, just as Russian ECMs have failed to stop long-range Ukrainian drones striking targets deep inside Russia’s territory.

Ukraine and the EU are also very different arenas when it comes to deployment of this tech. Ukraine’s airspace is closed to civilian aircraft. Not so in European countries, where large-scale jamming technologies can seriously mess with its extremely heavy civilian aviation traffic.

This caveat also applies to any drone detection systems, which may mistake a small civilian aircraft for a threat, and have to make the fateful decision whether to shoot at it or allow it to fly through.

Could cheap interceptor drones power the EU’s “drone wall”?

On the interception side, Ukraine has been at the forefront of developing small, cheap drones that can knock down long-range strikers, as well as their attendant observation units. Interceptor UAVs are a well-established and constantly updating part of Ukraine’s defensive strategy.

“They don’t have any effective countermeasures against UAV interceptors yet, but they’re searching,” Prokopchenko said on the podcast.

Interceptors run the gamut from plane-type systems, with reported speeds of up to 300 km/h, to even quadcopters. One Ukrainian developer of single-use interceptors, who asked not to be identified by name, produces machines ranging $1,500-$6,000 in cost.

In comparison, long-range Russian strike drones can cost in the tens of thousands.

Reusable interceptors, which can mount guns or explosive launchers to strike down hostile units, can potentially provide an even cheaper solution, in theory.

Furthermore, there’s a big tradeoff to consider between cost and effective range.

Another issue with the interceptor drone concept “is that it relies on skilled pilots,” wrote Fabian Hoffmann, a defense policy fellow at Oslo University. “While autonomous interceptor drones are under development, they are not yet mature, and their more complex system architecture will make them significantly more expensive.”

Short-range air defense systems: effective yet expensive to maintain

On the ground, the Ukrainians have also made use of fast wheeled vehicles networked together. These serve rapid response teams that can spread out along the drones’ flight paths, intercept them during an attack, and bring them down with automatic gunfire.

In the EU, defending countries are more likely to use weapon systems that are slightly less ad-hoc and more developed by defense contractors. These range from the venerable Gepard self-propelled gun, to the modern Skyranger, which can fire air-bursting rounds that saturate a target area with submunitions.

To protect more stationary targets, the EU states could employ fast-firing point-defense autocannons and other short-range air defense systems.

The more modern of these systems are relatively cheap to fire, but have a high up-front cost, with maintenance adding additional expenses.

Whether these systems can outcompete expendable drones in cost depends on specific production and deployment plans, among dozens of other variables.

Can legacy air defense systems adapt?

Expensive missile systems like the Patriot or France’s SAMP/T are likely to remain in use against enemy missiles, said Marc DeVore, who researched Russia’s invasion for the UK Foreign Office.

Indeed, Russians have frequently attacked Ukraine with a combination of weapons, flooding the airspace with hundreds of expendable drones, to allow a handful of ballistic or cruise missiles to slip through and do the real damage. Alternatively, air defense systems that focus on the missiles might miss more drones in the process.

DeVore told Euromaidan Press that manned fighter planes are still very capable of shooting down long-range strike drones with relatively inexpensive laser-guided rockets.

On the other hand, the high per-hour cost of flying a jet might offset this cost-effectiveness, depending on the operational parameters involved, other experts said.

DeVore further pointed out the difficulty of getting so many different solutions to cover a single airspace without posing a threat of friendly fire — after all, Ukraine reportedly lost at least one F-16 fighter in this way.

He suggested that one solution might be to delegate detection and interception duties to different parties, or create zones where one type of interception predominates. Alternatively, different layers of altitude can be protected by different systems. 

Integration is the main challenge

By themselves, these solutions are just building blocks. To build a “drone wall” of any kind, ”you have to integrate everything from the largest Patriot to the smallest interceptor drone,” Kirill Mikhailov, a researcher with the Conflict Intelligence Team, told Euromaidan Press. “All of this requires cooperation and collaboration on a so-far unprecedented level.”

That may be putting it lightly. Every analyst who spoke to Euromaidan Press emphasized both the critical need and the great challenge of creating interoperability solutions to process data quickly and figure out who needs to be shooting what. The Ukrainians have led the way here as well, with their battle management systems like Virazh and Delta.

To incorporate these lessons, European allies likely need to adopt automated big data solutions, DeVore said.

Data architect Daniel Connery emphasized the need for a “drone-agnostic software layer” with “secure, interoperable application programming interfaces.”

“Imagine a border sector where one vendor’s drones patrol during the day, another’s at night, and a third provides thermal reconnaissance,” Connery wrote to Euromaidan Press.

“If each has its own control software, integrating their feeds, scheduling rotations, and handing off tasks between fleets becomes nightmarish.”

The need to evolve

But even all of the above is not sufficient. A next-generation drone defense system of the kind the EU is envisioning has to be able to evolve dynamically over time, in response to rapid developments, not just in technology, but enemy strategy and tactics.

Again, Rubicon is the best example. “I’d say the Rubicon problem is much broader than just countering our UAVs that shoot down scouts,” Taras Tymochko, a consultant with the Come Back Alive Fund, told the Dronefall podcast.

“Because Rubicon, I’d put it this way — they taught the enemy how to fight.”

Ukrainian attack drones struck an S-400 Triumph air defense system in Russia’s Kaluga Region, destroying a missile launcher and its attendant radar unit, Ukraine’s Special Operations Forces (SSO) reported on 22 September.

The SSO wrote that they identified the missile system during a reconnaissance mission, got visual confirmation, and were cleared to fire on the target during the overnight operation on 5 September. 

Open-source intelligence from the monitoring community Oko Gora placed the target between 150 and 250 kilometers from Ukraine’s border, United 24 reported.

Special forces also reported destroying components of S-400 systems in occupied Crimea in late August and late June, taking down multiple radar components and one launcher. 

In January, the Ukrainian General Staff reported destroying S-400 radar equipment in Russia’s Belgorod oblast. Similar strikes picking Russia’s S-400s apart were also reported in the preceding years. 

The S-400 Triumph is Russia’s most advanced air defense missile system. It is reportedly able to track and destroy aircraft, missiles, and drones hundreds of kilometers away. A single battery, consisting of multiple launchers and their loading and targeting vehicles, is estimated to cost $1.2 billion. 

Military experts speaking to the Kyiv Independent in September 2023 said that while capable, S-400s are vulnerable to stand-off and stand-in jamming and may be confused by small, slow-moving targets like drones. To operate safely, the system needs to be layered with short- to medium-range air defenses.

Ukrainian special forces also criticized Russia’s organizational doctrine when deploying the systems.

Europe faces a problem it’s never solved: how to stop thousands of cheap drones without bankrupting itself firing million-dollar missiles at styrofoam.

Ukraine already knows the answer.

The European Union’s “drone wall” defense initiative, reinvigorated just hours after Russian drones violated Polish and Romanian airspace on 10 September, could elevate Ukraine from aid recipient to essential defense partner— if said allies can overcome the technical and organizational challenges of such an ambitious project.

The scale of the ambition involved is hard to understate. “It requires a whole paradigm shift,” Kirill Mikhailov, a military researcher with the Conflict Intelligence Team, told Euromaidan Press. Brigham McCown, a senior fellow at the Hudson Institute, called it a “monumental undertaking.”

If successful, the initiative can further accelerate Ukraine’s transformation from a beleaguered country asking for aid into an important part of European defensive strategy. Ukraine can help develop the technology, industrial practices, and organizational doctrines required for a new way of air war.

The need to integrate weapon systems and practices could also bind Ukraine even closer to its allies and help develop additional trust, potentially helping its arms-producing companies develop.

Why Ukraine holds the keys to Europe’s defense future

For Europe, it’s a way to evolve from reliance on big, expensive weapons, a doctrine that’s aging in the face of massed cheap unmanned aerial vehicles now swarming the skies.

“It should be pretty obvious that you don’t shoot down styrofoam drones with $2 million missiles,” Mikhailov said. “Thing is, that is all the Europeans currently have.”

Andrius Kubilius, the European Commissioner for Defense and Space, acknowledged a similar point at Ukraine’s Defense Tech Valley expo in Lviv on 17 September.

“We understood a simple truth: we do not have those capabilities that Ukraine has on how to fight against drone invasion,” Kubilius said. “We have F-16s, we have F-35s, we have all other weapons, but we do not have those capabilities.”

It’s unclear to what degree the EU intends to protect Ukraine with this initiative. Kubilius said this curtain must extend “across the entire EU Eastern flank.” This language suggests the possibility that Ukraine will be left to protect its own airspace alone as the EU turtles up.

Furthermore, Kubilius told Euromaidan Press that “each country on the frontline needs to have its own companies to produce,” making unclear the role of Ukrainian developers in the EU’s strategic air defense planning.

Depending on how strongly the EU countries favor local companies, this could make the drone wall more costly and difficult to build.

Kubilius told Euromaidan Press that it was too early to estimate the cost or build time of the initiative, but said that some public estimates by analysts suggest it could be done within a year.

Several defense experts who spoke with Euromaidan Press believe that multiple years are a likelier estimate.

First steps

NATO has been looking into a drone defense initiative throughout the full-scale invasion, military insiders told Euromaidan Press.

The term “drone wall” has cropped up in the news for months. French company Altares, speaking at the Defense Tech Valley, said it’s been working on it for six months, together with the Alliance.

But the rhetoric around a drone wall went into overdrive after the incursion of Russian drones into Polish and Romanian airspace on 10 September. Hours following the attack, in her 2025 State of the Union address, European Commission President Ursula von der Leyen revealed plans for a new “Eastern Flank Watch.”

This would include the “drone wall,” which she said would stretch down from the Baltic Sea to the Black Sea.

Von der Leyen said the EU would set up a “drone alliance” with Ukraine, funded by 6 billion euros. This will fall under the aegis of the G7-led Extraordinary Revenue Acceleration initiative, which is supposed to provide about 45 billion euros in financial support to Ukraine, with the EU contributing 18.1 billion euros.

Von der Leyen said that a roadmap for “getting new common defence projects off the ground” will be presented at the next European Council on October 23-24, with an eye towards setting clear goals for 2030.

Meanwhile, Ukraine and Poland agreed to establish a joint operational group on unmanned aerial systems, with representatives from both countries’ armed forces.

What’s in it for Ukraine: from aid recipient to tech powerhouse

There are multiple potential upsides for Kyiv becoming Europe’s defense tech guru. For one, it could help Ukrainian companies grow and expand.

“Ukraine has the silicon valley of this kind of technology, type of know-how and can become the world leader in drone and anti-drone tech, detection, counter, and this has very broad application beyond the current conflict,” McCown said.

Euromaidan Press spoke to several Ukrainian drone producers, who said that despite the government’s stated intention to procure all weapons produced from accredited and trusted contractors, the state is not able to afford their entire production capabilities.

Some Ukrainian companies are longingly eyeing the export market, but Ukraine’s hard restrictions on the import of military tech doesn’t allow it. The drone wall initiative may change things in that regard.

“The government hasn’t been warm to the idea of lifting the arms export ban,” Mikhailov said. “Now that Zelenskyy can paint himself the savior of Europe and make Ukraine indispensable for European security, I have few doubts he would greenlight it if asked.”

DeVore said that Ukraine’s innovation with drones, machine learning, AI and battle management is absolutely deeply respected. Allies are “very hungry to learn these lessons and one can think of this as a form of soft power or influence that Ukraine has.”

However, when asked if this might translate into more negotiating leverage for Kyiv, DeVore doesn’t believe so. “I think those allies that most appreciate and are most eager to learn these lessons are those that already have really close relations with Ukraine and are doing as much as feasible to help Ukraine,” he said.

Countries that are less worried about Russian attacks, such as Spain, Italy, and Hungary may not be swayed enough to change the overall status quo.

“This is a good thing for Ukraine, because that would build trust, interdependence, interoperability,” Mikhailov said. “It can be like the backbone of Ukraine’s further participation in NATO.”

The head of a Ukrainian company that builds interceptor drones, who did not wish to be identified for security reasons, said he hopes a closer working relationship between Ukraine and its allies, as part of the drone wall initiative, could help isolate Russia.

The massive technical challenges ahead

The obstacles the EU must overcome to build the drone wall are as almost as diverse as the hardware involved.

The most obvious challenge is logistical — drones require management of their power supplies, weather resilience and durability. Many thousands of drones must be built, deployed and serviced on a regular basis, with each requiring batteries, charging stations and redundancy plans for failure.

Data architect Daniel Connery said that the truly defining obstacle would be the creation of a software layer that can manage inputs from so many different systems and turn them into one coherent defense network, which is secure from outside tampering.

“Without a unifying software layer, you don’t have a ‘wall’ — you have scattered bricks,” he wrote to Euromaidan Press.

Ukrainian networked battlespace systems like Virazh and Delta may show Europeans the way forward, experts pointed out.

Manufacturing priorities are also bound to come up. After decades of consolidation, Europe has a small number of large defense contractors. These types of companies aren’t the most nimble when it comes to pivoting from producing few expensive weapons to many cheap ones.

Most analysts agreed that smaller companies will rush to fill that space, whether it’s local European firms that manufacture civilian equipment, or Ukrainian firms opening subsidiaries.

Speaking at the Defense Tech Valley, some Western firms complained about bureaucracy and confusing official procedures when it comes to doing business in each others’ territory. Legal, administrative and security clearance questions likely need to be resolved before cooperation can be scaled up to greater heights, experts said.

Ukraine might also need to accelerate its judicial reforms, as its legal environment is an Achilles’ heel when it comes to foreigners doing business with the country.

DeVore said that one problem with European defense programs is the dilemma between spending in Europe and spending efficiently. Systems produced in European nations are more popular with policymakers, but they aren’t the most cost-effective solution.

DeVore believes the drone wall is “fully feasible, it just requires some combination of political will and money.”

“Those two are inversely correlated,” he added. “The more political will the West has in putting this together, the cheaper it is.”

Alya Shandra, the editor-in-chief at Euromaidan Press, contributed reporting.