Leonidas: The High-Power Microwave Weapon That Could End the Drone Warfare Revolution

Warfare in the 2020s has been fundamentally reshaped by the rise of drone technology—from handheld quadcopters providing real-time intelligence to small ground units, to legions of kamikaze drones capable of flying hundreds or thousands of kilometers before detonating, to cheap crowdfunded sea drones turning formidable warships into wreckage. Modern militaries have struggled to counter them, unable to afford losing expensive hardware to off-the-shelf devices that cost a fraction of the price. But the same technological dynamism that fueled the drone revolution may also produce its antidote.

Among the most promising counter-drone systems in development is Leonidas, a high-powered microwave energy weapon built by the American startup Epirus. Designed to create a protective bubble that fries the electronics of any hostile drone that enters its radius, Leonidas represents a potential paradigm shift in battlefield air defense—a real-life force field that could put the drone revolution in checkmate, if it can keep pace with the rapidly evolving threat.

The Rise of Consumer Drone Warfare and the Urgency Behind Leonidas

Consumer drones have become a major problem for global militaries in the span of the last two to three years, but their combat potential has been a matter of discussion for roughly a decade. Starting with the wars of the 2010s—particularly across the Middle East in the violent aftermath of the Arab Spring—insurgencies, terror organizations, and rebel groups began using commercially available drones almost as soon as they could be purchased off shelves. These devices were easy for a group’s foreign supporters to buy abroad and send as direct donations, and at times they could be acquired in-country as well.

As early as 2013, Hezbollah in Lebanon worked out that grenades could be dropped from consumer-grade drones. Although modifying drones to carry weapons was expensive in time and money, it was still vastly cheaper than procuring manned aircraft or sophisticated UAVs. By 2015, the Islamic State was using drones in Syria, and by 2017 in Mosul, the group had turned them into a genuine menace for their adversaries. Central and South American cartels adopted them for reconnaissance and narcotics smuggling, and in 2018, Venezuelan President Nicolás Maduro came under attack by a pair of commercial drones in an assassination attempt.

Global media was already picking up on the trend. One particularly notable contribution came from the national security outlet Defense One, which published an article in 2017 entitled “I Could Kill You with a Consumer Drone,” citing private research showing a rapid increase in the use of drones in combat zones by terrorist insurgencies. The US military’s own attempts to experiment with consumer drones were halted due to cybersecurity risks, but analysts on both sides of the debate warned that ignoring the technology would only allow the problem to grow. It was in this environment—where much of the world remained oblivious and most observers treated the trend with detached curiosity—that a select few saw an opportunity.

The Founding of Epirus and the Birth of Leonidas

Those who recognized the trajectory of drone warfare founded a company called Epirus, named in homage to an ancient Greek state that rose to prominence during the 270s BCE. Today, Epirus describes itself as a “Neo Prime,” an organization that works to “innovate, build and deliver ahead of the need” in response to the challenges of modern asymmetric warfare. But in the months after its founding in 2018, the startup was quietly assembling talent from across the American defense and technology sectors—people who understood where the new trend toward drone warfare was headed.

The US military hadn’t yet issued any public calls for a system capable of nullifying the threat posed by cheap aerial drones. But Epirus anticipated that as soon as those same drones were turned against American forces, the Pentagon would recognize the urgency of procuring such a device. When that moment came, Epirus intended to have an answer already waiting.

The answer they built goes by the name Leonidas, honoring another figure of ancient Greek history: Leonidas of Epirus, the tutor to Alexander the Great. Unveiled in 2020, the Leonidas system was the first and most promising answer the United States had—either public or private—to neutralize the threat of aerial drones. The Pentagon showed interest quickly. By 2021, the General Dynamics corporation was working with Epirus to make Leonidas into a mobile system.

A few months later, it was modified for airborne combat use. By the first weeks of 2023, Epirus was on the hook to deliver several prototypes to the US military as quickly as possible.

It was a remarkably rushed process, atypical for a slow and churning military-industrial complex that prefers to contract with its well-established partners. But as predicted, the Leonidas system had arrived at precisely the moment when the Department of Defense was recognizing a critical need. And as promised, the technology proved capable of addressing the problem America barely knew it had.

How Leonidas Works: High-Power Microwave Energy and Directed EMPs

Perhaps the best way to understand the Leonidas system is through the lens of another famous Greek historical figure of the same name: Leonidas I, ancient King of Sparta. Leonidas I and his Spartan warriors gained victory in battle by using their shields as weapons—for defense, absolutely, but also as a powerful means to gain an advantage in counterattack. The tactical philosophy behind the modern-day Leonidas system is much the same. It uses a directed-energy weapon rather than an interceptor system to take out incoming threats, but rather than being a point-and-shoot offensive weapon, Leonidas is designed to provide defensive area coverage—creating not so much a contiguous force field as an area of denial where no unfriendly drone system can operate.

At its core, the Leonidas system fires high-power microwave energy in beams that create an electromagnetic pulse, or EMP. EMPs are nothing new in modern warfare, and their effects are well known—primarily their ability to disable electronic systems. But unlike the natural EMPs from lightning strikes or the uncontrolled EMPs resulting from nuclear detonations, the EMPs generated by Leonidas can be channeled with precision.

Cutting in a wide beam, they can fry everything in their path, neutralizing an oncoming drone swarm all at once. Alternatively, they can focus on precise individual targets, sniping drones out of the sky one by one as soon as they violate a given perimeter. This represents a massive improvement over any laser-based system, which would offer only the capability to fire against a single target at a time.

Leonidas achieves its compact form factor by using specialized transistors rather than traditional magnetrons to generate its microwave beam, making the system considerably smaller than would otherwise be expected of a weapon of this kind. At a relatively low cost of energy expenditure, it can focus a beam for extended durations or fire off in rapid succession. A digitally beamformed antenna keeps the beam tight and highly precise, reducing the likelihood that nearby friendly drones will be impacted when the beam is targeted against a single foe.

The system can fire very rapidly without overheating, and its effect on a target is near-instantaneous—there is no need to train the beam on the target for any length of time. It doesn’t require reloading, and its voltage is low enough that humans nearby aren’t endangered by its emissions. Any consumer-grade drone that enters Leonidas’ protective bubble will be fried, regardless of the specific internal electronics it features.

Platform Integration: From Stryker Vehicles to Airborne Pods

The advantages of the Leonidas system extend well beyond its core directed-energy capability. Initially envisioned as a towed trailer, Leonidas has now been adapted to the Stryker, an eight-wheeled armored fighting vehicle that has been in America’s military employ since 2002. The Stryker is well-armored, armed for its own defense, and capable of driving under its own power at speeds up to sixty miles per hour—nearly a hundred kilometers per hour—while requiring minimal crew to operate.

The software Leonidas carries offers a range of benefits, but most important of all is its ability to distinguish between friend and foe. Rather than simply creating an indiscriminate anti-drone force field, the system creates a safe zone for friendly drones to operate while adversary devices have little hope of survival. The friend-or-foe system can be programmed to fit a given situation—enforcing a no-fly zone, for example, or ignoring adversaries outside a certain critical zone.

Beyond the Stryker-mounted variant, the system has been adapted into an aerial attachment pod, giving it the option to be fitted onto a heavy-lift drone and defend positions from midair. It is also in the process of being miniaturized and can, at this stage, be fitted into the back of a pickup truck without too much trouble. The technology is ruggedized, meaning it can take a beating and continue to function, while the Leonidas Pod is designed to integrate with all manner of existing UAVs and could likely be grafted to manned aircraft as well.

Critically, because Leonidas targets the electronic systems of a drone directly rather than simply cutting it off from radio operators, it is equally effective against fully autonomous drones that don’t require active operator control to function. Tests have also demonstrated that Leonidas can disable a sea vessel’s outboard motor, extending its utility beyond aerial drones to maritime threats and essentially any other electronics an operator could point it at.

Modularity and Future-Proofing

Perhaps the most important design element of the Leonidas system is its focus on modularity and easy adaptability. This is a feature of many modern US military technologies, especially those that rely on software to function. The United States would rather avoid the problems it faces with platforms like the F-22 Raptor, a highly sophisticated aircraft that still runs on software that was current in the 1990s.

Like many more modern systems, Leonidas is built in a way that should make its hardware compatible with future enhancements. Its software systems can have new elements grafted on, or can be outright replaced or overwritten as necessary in future decades. The hope is that as new capabilities become available and as adversaries develop better methods of dealing with Leonidas, the technology can be quickly updated and rushed back into the fight without skipping a beat. In a domain where the evolutionary cycle of warfare demands constant adaptation, this modularity could prove to be Leonidas’ most enduring advantage.

Prototypes Delivered and Real-World Testing in the Middle East

As of now, Leonidas has gone through several iterations. While the airborne Leonidas Pod is still being adapted to heavy-lift drones, the ground-based version is ready for testing. In January 2023, the United States awarded Epirus a contract worth 66 million dollars after the company beat out six different competitors, with the expectation that the funds would be used to develop four prototypes as quickly as possible. Fourteen months later, all four prototypes had been delivered, and for approximately half a year, they have been in the hands of the US government.

According to statements by the US Army’s Chief of Staff, General Randy George, some of the prototypes are now in the Middle East for real-life testing. This is a threat environment where Iran-backed militias in Syria and Iraq have launched frequent drone attacks against US service members using Iranian-designed technology. In January 2024, one such attack killed three Americans and injured forty-seven at an outpost called Tower 22. Although not entirely confirmed, it is likely that the Tower 22 attack was a motivating factor in seeing the Leonidas system tested in real-life conditions, since the attack was carried out by a drone that was not correctly identified as an enemy and intercepted on approach by the outpost’s pre-existing air defenses.

Public information on how Leonidas is performing in those austere conditions is not yet available. However, the system faces a rather beatable competitor in another directed-energy weapon—a laser system that also mounts on Stryker vehicles for similar air-defense missions. Those laser systems have reportedly run into trouble because incorporating higher-powered lasers into rugged machines where they must withstand heat, wear, and tear has proven difficult, while the lower-powered lasers that work better have only been successful when stationary.

In test conditions, Leonidas has already demonstrated that it can deal with both single drones and drone swarms, including ones described as “utilizing a range of increasingly complex flight patterns.” If it can replicate that performance in the field, it may become America’s leading option for large-scale procurement at a moment when effective anti-drone capabilities are urgently needed.

Deployment Potential: From Base Defense to the Front Lines

When Leonidas enters military service, it will grant US forces near-full protection against enemy drones in the areas where it is deployed. The system’s potential applications are extensive. It can watch over military bases like the Tower 22 outpost, providing constant threat detection and interception without interfering with friendly drone systems. It can be deployed at border regions and local checkpoints, offering valuable overwatch for troops at fixed and exposed sites that are often the most vulnerable to attack.

Leonidas can be stationed at critical infrastructure locations such as dams, power plants, and more—potentially not just in military operations abroad but within the United States, where national security analysts have warned of domestic extremists shifting their focus toward the nation’s vulnerable power grid. It can be pointed at technology other than enemy drones, taking out jamming systems, enemy radar, or essentially anything else that could be shorted out with an EMP.

Because it is mounted on mobile platforms—currently the Stryker, but potentially either heavier armored vehicles or lighter, more nimble ones—Leonidas has the potential to follow troops into battle, even to the front lines. Ground-based Leonidas systems can be paired with the airborne Leonidas Pod, providing a multilayered, integrated defensive perimeter with a greater radius and more anti-drone power. The United States has seen firsthand in Ukraine and elsewhere how drones have become a constant reality on all sides of a battlefield. For American soldiers to be equipped with a highly mobile system that can render enemy drones irrelevant would confer a critical advantage over just about any military in the world.

Export Potential: NATO Allies, the Indo-Pacific, and Ukraine

Leonidas’ potential extends well beyond the borders of the United States. American allies abroad would likely be eager to find such a system in their own arsenals. The more easterly members of the NATO alliance, who expect to be on the front lines in any future conflict with drone-reliant Russia, would be particularly interested.

South Korea, Japan, Taiwan, the Philippines, Vietnam, and other US allies in the Asia-Pacific would probably be just as enthusiastic about obtaining the technology. For Israel, America’s foremost ally in the Middle East, a system like Leonidas could be indispensable as a final element to complete its air-defense shield over the country.

Perhaps the most interesting potential customer is Ukraine, where a significant proportion of experts on the current war with Russia expect the conflict may last for years to come. Soldiers on both sides have frequently described the war as a testbed for all manner of advanced weapons, and when it comes to advanced weapons, perhaps not a single one would be as potentially game-changing as Leonidas. The system’s ability to neutralize the drone swarms that have become a defining feature of the conflict could fundamentally alter the battlefield calculus. If the people behind Epirus would like to become very successful very quickly, advocating for Leonidas as a likely export product would be a compelling place to start.

Limitations and Vulnerabilities

Despite its transformative potential, Leonidas is not a magic bullet. The system has inherent limitations that must be acknowledged. While it has been miniaturized to a size that fits in the back of a pickup truck, pickup trucks cannot go everywhere. Even smaller versions—the sort of thing that could fit in an oversized backpack or on the back of an all-terrain vehicle—are not yet forthcoming. This means that in certain environments, Leonidas will be unable to deploy, at least for now.

Those environments include truly austere front-line combat zones, especially heavily forested areas, snowy or swampy terrain, and places with difficult-to-navigate geography. Unfortunately, these are some of the places where small, cheap, and highly maneuverable reconnaissance or kamikaze drones can make the biggest impact. The limitation also extends to small-unit operators, especially Special Forces troops operating far afield in difficult environments, who will be unable to take Leonidas—at least in its current form—into combat with them.

The system also has critical vulnerabilities that will need to be safeguarded. Its friend-or-foe identification system is a particular concern. If an adversary learns enough about how that system works, they could potentially develop the means to spoof Leonidas with signals indicating that hostile drones are friendly, when in reality they are anything but. Protecting the integrity of this identification system will be essential to maintaining Leonidas’ effectiveness.

The Evolutionary Cycle: Countering the Counter

Although Leonidas clearly has the potential to upend the current drone-based order of modern combat, it is important to recognize that the system—as it exists now—represents just one step in a long evolutionary cycle. This is how warfare works: one side develops a certain capability, the other side figures out how to counter it, the first side develops a counter to the counter, and the cycle continues.

Leonidas is a valuable answer to the problems that today’s drones pose, and it remains to be seen how any modern drone could get past a weapon that fries its internal systems. But if drones can be built in a way that hardens them against EMPs, or in a way that uses components less prone to being instantly fried, then Leonidas in its current form will not be enough. It falls to the drone engineers who seek to build those weapons to find ways through the Leonidas system, and that process will take time. But it will happen eventually, and the cycle of evolution will continue.

This is precisely why Leonidas’ modular design philosophy is so critical. Built to be rapidly updated and enhanced before being sent back into the field, the system is designed to evolve alongside the threats it faces. With any luck, that means future versions of Leonidas will still be the answer when adversaries develop hardened drones. But that remains to be seen, and it is up to the Epirus team and their allies in the Department of Defense to stay ahead of the curve as best they can.

Outlook: Why Leonidas Appears Destined for Service

In the near term, it appears unlikely—at least from the outside—that Leonidas would not enter service in a combat role sooner rather than later. The capabilities it offers are simply too compelling. Its design, internal contingencies, and various iterations are too well thought out. The modularity of the entire system means that although there are no guarantees, the United States can be confident it is purchasing a system that will be meaningful for decades rather than just years.

The US has wanted directed-energy tools for a very long time, and the entire world has been trying to figure out what to do about drone technology in record time. The Leonidas system is not just on the cutting edge—it is the cutting edge. If it delivers as promised in the real-world testing now underway in the Middle East, the system could become something of a household name in the defense world very soon. In a landscape where the drone revolution has put the world’s most powerful militaries in check, Leonidas may represent the checkmate from the opposing side—provided it can keep evolving as fast as the threats it was built to stop.

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Frequently Asked Questions

What is Leonidas and how does it work?

Leonidas is a directed-energy weapon system developed by Epirus that fires high-power microwave energy beams to create targeted electromagnetic pulses (EMPs). These EMPs instantly fry the internal electronics of drones, disabling them without physical projectiles. The system uses specialized transistors rather than traditional magnetrons to generate compact microwave beams, with a digitally beamformed antenna keeping the beam tight and precise. It can operate in wide-beam mode to neutralize entire drone swarms at once, or focus on individual targets for precision strikes, and features friend-or-foe identification software so allied drones can operate safely within the same area.

What platforms can Leonidas be mounted on?

The primary ground-based version mounts on the Stryker eight-wheeled armored fighting vehicle, which can travel up to 60 mph while providing armor protection and requiring minimal crew. An airborne variant called the Leonidas Pod is being adapted for heavy-lift drones and could potentially be fitted to manned aircraft as well. The system has been miniaturized to fit in the back of pickup trucks, though smaller man-portable versions for Special Forces operating in remote environments are not yet available.

What is the current deployment status of Leonidas?

In January 2023, the US awarded Epirus a $66 million contract to develop four prototypes after the company beat six competitors. All four prototypes were delivered by March 2024. According to US Army Chief of Staff General Randy George, some prototypes are currently undergoing real-world testing in the Middle East, likely motivated by the January 2024 Tower 22 attack where an Iranian-designed drone killed three Americans and injured 47 after not being correctly identified by existing air defenses.

What are the advantages of Leonidas over laser-based anti-drone systems?

Leonidas can target entire drone swarms simultaneously with wide-beam mode rather than engaging one target at a time; it has near-instantaneous effect without needing to train the beam on targets for extended periods; it does not require reloading; it fires rapidly without overheating; and it operates at relatively low energy cost. Competing laser systems mounted on Strykers have struggled because higher-powered lasers have difficulty withstanding heat, wear, and tear in rugged conditions, while lower-powered lasers have only succeeded when stationary.

What are the main limitations of Leonidas?

Key limitations include inability to deploy in austere terrain like heavily forested areas, swampy regions, or difficult geography where pickup trucks cannot travel, and the lack of man-portable versions for Special Forces in remote environments. The friend-or-foe identification system is a potential vulnerability if adversaries learn to spoof it. Longer-term, adversaries will eventually develop EMP-hardened drones that can defeat the current system — which is why Leonidas’ modular, software-upgradeable design philosophy is critical to ensuring the weapon can be updated quickly as the threat evolves.

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