Keith L. Carter
Jen Spindel
Ukraine’s Operation Spiderweb reinvigorated debates about the utility of small drones and the futility of defending against them. Ukraine loaded first-person view (FPV) and remotely piloted small drones onto transport vehicles infiltrated into Russia, remotely opening the crates carrying the drones to target Russian airfields as far as 4,000 km away from Ukraine. The operation involved 117 drones and attacked Russian strategic bombers including the Tu-95, Tu-22M3, and Tu-160, as well as the A-50 surveillance plane. US Air Force Chief of Staff David Allvin called the operation a “wake-up moment” because “seemingly impenetrable locations, maybe, are not.”
Operation Spiderweb was as much a logistical success as it was a successful demonstration of small drone capabilities. Planning for the operation began 18 months prior, and it relied on in-depth knowledge of Russian cargo and transportation routes. But the operation was a clear example of precision strike with fairly unsophisticated and comparatively cheap weapons. What does Operation Spiderweb mean for the future of air defense? We outline how the United States and allied air forces should fundamentally rethink the risks and opportunities posed by small drones.
First, while Operation Spiderweb used small drones at unprecedented scale, it is not the first time that cheap weapons have “outsmarted” more technologically advanced ones. During the 2020 war in Nagorno-Karabakh, Azerbaijan retrofitted old Soviet planes to be flown remotely and used them as an autonomous Wild Weasel to bait Armenian air defense into firing. This revealed the location of Armenian air defense systems, and allowed Azerbaijan to use its modern drones to target these locations. In 2023, the US panic over Chinese spy balloons floating over the country show the dilemma of responding to lower-tech airborne threats. The balloons used US internet providers to communicate, but posed a response dilemma: what sort of damage might occur if the United States shot down the balloons while they were over populated areas? Harkening back to the WWI, the United States used F-22s as high tech ballon busters to shoot down the Chinese balloons off of the US coastline, but the slowness and non-traditional flight paths of the balloons posed problems for US air defense systems that expect to defend the homeland with fighter jets and missiles. As with Operation Spiderweb, these incidents represent the dilemma explained by General Bryan Fenton, the commander of US Special Operations Command: “Our adversaries use $10,000 one-way drones that we shoot down with $2 million missiles. That cost-benefit curve is upside down.” The future of air defense will have to reckon with this dilemma.
The Vulnerabilities of Traditional Air Defense
The first air defense vulnerability revealed by Operation Spiderweb is the devastating capability of drones to target and destroy air assets on the ground. Russian planes were parked, as normal, at their air bases, ready for takeoff. Airfields, airplanes in the open, and stationary targets are more difficult to protect. Site hardening for protection is a possible solution but entails tradeoffs. While air forces could harden airport and plane storage, and could keep more planes inside protected warehouses, this increases the time needed to get a plane ready to take off. Radars specialized to detect small drones is also an option, but even if there were better radar detection, the traditional response of using sophisticated weapons to shoot down small drones does not scale up. In a drone swarm, where hundreds or thousands of drones are sent to a target, there are not enough missiles to target each drone. And even if there were, the monetary cost of such missiles and the ability for the United States or allies to produce the missiles the scale needed is a limiting factor.
Current air defense technologies and strategies were not designed to face slower-moving small drones; they were made to quickly identify, track, and fire upon fast-moving targets. The Shahed-136 loitering munition, for example, flies at a maximum of 120 miles per hour, and can move in often unpredictable patterns. The “hard kill” air defense solution of firing on these weapons is incredibly difficult because of the size and speed of the target – small drones can often look like birds on radar because they fly slow and low.
Rethinking Air Defense
While traditional air defense like the Patriot missile system (or its Russian counterpart, the S-400) are overkill for small drones, both Ukraine and Russia have turned to surprising options to counter the new drone threat. World War II-era anti-aircraft guns have found new life in Ukraine. Both sides have been using S-60 anti-aircraft guns since 2022, and Ukraine has fitted the Zastava M75 anti-aircraft gun (also of WWII vintage) with thermal and daylight sights. Should the United States and its allies turn to similar, lower cost and lower tech, anti-drone solutions? Will flak, most likely with AI enhanced targeting and firing solutions, have a renewed moment in the sun?
Against drone swarms flak may have numerous benefits over more advanced air defense. First, as was the case with B-17 and B-29 bombers facing flak in WWII, you don’t need a bullseye to cause damage to a drone. Flak fell out of favor because of advances in airplane speed and the thickness of airplane skin. Drones do not have this; they are in many ways more similar to early planes than they are to more modern fighters and bombers. Flak can penetrate and disable small drones, and does not require the accuracy of Patriot missiles. Against a drone swarm, enough flak could disrupt the swarm; against FPV, flak can cause piloting difficulties and damage that would prevent the drone from reaching its target. Even if flak does not directly damage the drones, enough of it in the air can make it difficult for the drone to identify ground targets.
A second benefit to flak is its cost relative to the drones it will be targeting. Flak is much cheaper than modern air defense systems, and goes a long way toward solving the cost-benefit curve mentioned by General Fenton. Self-propelled anti-aircraft guns like the ones used in Russia and Ukraine are mobile, easy to set up, and easy to learn. They could be more readily deployed to protect forward areas where US and allied troops are operating, and would be able to defend the coastal homeland.
Flak does not have to be delivered from older WWII systems. BAE Systems, for example, produces the TRIDON Mk2 40 mm anti-aircraft gun. As BAE explains, the TRIDON is the modern evolution of a system first used in 1936, and can be used against drones and cruise missiles as well as ground-based targets. Rather than pack the most advanced technology into an expensive system designed to target adversary jets and bombers, the TRIDON is a relatively simple defensive weapon that fills the gap in air defense and is highly in demand in Ukraine and Europe. United States arms producers should consider this type of mid-range type anti-aircraft gun as an integral component of a modern integrated air defense system, as its capabilities are essential for defending against small drones and drone swarms.
A return to old weapons is not the only way to rethink air defense. Rather than focusing on a hard kill strategy – being the best at shooting things out of the sky – modern air defense needs to think about layered prevention. This would require leveraging cyber and communications technology to interfere with drone communications. After all, both Operation Spiderweb and the 2023 Chinese balloon incursion relied on local cell phone networks. A layered prevention strategy would first involve using cyber capabilities to interfere with drone command and control. This does not require taking every single drone offline every time, but rather interfering enough to make the remote pilot or algorithm unable to accomplish its goals. Drones could be disabled, or their communications could be interfered with to cause them to fly to a benign location.
The second arm of layered prevention would require tracing signals to identify where the pilots are located. Both Russia and Ukraine have used cellphone signals and acoustic sensors to triangulate where drone operators are. This strategy obviously works best when two sides are fighting in close proximity, but companies in the United States and abroad are working on ways to broaden the use of cellphones as both jammers and detectors. Signals identification is an appropriate place for sophisticated and advanced technologies. When paired with flak defense, it would allow the United States to have an active defense against drones and the ability to locate the drone operators.
What seems certain is that the hype about drones is not overblown. Successful drone usage does require logistical and infrastructure support; without the months of planning and knowledge of Russian transportation, Operation Spiderweb would not have been successful. But Ukraine disabled one third of Russia’s strategic cruise missile carriers, and targeted Russian air bases as far away as Olenya in Murmansk (1900 km) and Belaya in Urkutsk (4000 km) all with FPV and small drones. Recent reports attribute nearly 90% of front-line casualties in the war in Ukraine to FPV and short-range drones. To defend against these weapons, the United States needs to be willing to fundamentally re-think air defense by realizing the limits of sophisticated systems designed to target missiles and jets, and understanding the real threats posed by drones that many once dismissed as inconsequential to the future of war.
Jennifer Spindel is assistant professor of political science at the University of New Hampshire.
Keith L. Carter is associate dean of the Naval War college at the Naval Postgraduate School.
The views expressed are those of the author and do not reflect the official policy or position of the US Air Force, the Naval War College, the US Navy, the Department of War, or the US government.