Around dusk on a cool evening at San Diego’s downtown Ruocco Park, few people take notice as two men set up a couple camera tripods and place some medium-sized boxes on the ground next to their parked truck. The men aim a device that looks like a camera across the water, where, visible directly across the bay and just under a mile away, the aircraft carrier USS Abraham Lincoln (CVN-72) is moored alongside Naval Air Station North Island.
The camera-like device is actually a sophisticated laser rangefinder coupled to a highly accurate GPS unit, which allows for precise measurement of position data. As one of the men records this data on a computer, the other opens the crates, revealing several small drones. These are nearly unmodified commercial Da Jiang Innovations (DJI) Matrice multicopters. He begins installing batteries and powering on the drones.
One of the men checks his watch and finishes inputting the position data gathered from the rangefinder into the drones. With a nod to each other, they press buttons on the flight controllers, directing the drones to fly their preprogrammed flight paths. The men quickly walk to their vehicle as both Matrices lift off.
The drones fly quickly across the bay, their position and link status lights disabled prior to launch. It takes them less than a minute to reach their destination: the communications and radar antennas located above the Abraham Lincoln’s island. Control signals from ports on the Matrices—designed to allow for control of external sensors—apply voltage to detonators, igniting improvised explosives made from fireworks and bundled to the bottoms of the drones. A spray of nails and ball bearings blows outward, shredding the sensitive communications equipment necessary for flight operations and fleet command and control. Not every communication system is destroyed, but the Abraham Lincoln is now significantly mission-degraded.
Meanwhile, a swarm of small drones has moved unnoticed across the bay toward the ships at the 32nd Street docks and are ramming into exposed radar array panels at high speed or exploding over communication arrays and surface-search radars.
At Point Loma, small drones begin smashing into exposed submarine periscopes and radio masts, twisting and bending them so they can no longer be retracted into sails. Over the North Island runways, drones drop metal fragments before crashing into the engine intakes of stationary transport aircraft. The entire operation takes less than five minutes from launch to completion.
Similar events occur nearly simultaneously at multiple Pacific fleet concentrations and air bases. In all cases, the actual destruction is minimal, but a significant portion of the deployable U.S. military has been rendered temporarily helpless in one night using cheap, commercially available assets.
Even as the force protection reports are still flowing in from around the Pacific Rim, Indo-Pacific Command (IndoPaCom) staff are confronted with an urgent report from the Taiwan Strait—the People’s Liberation Army Navy is crossing in force. The dilemma is real—can the United States successfully oppose a determined amphibious assault solely using the available afloat resources? The rapid-deployable 25th Infantry Division and 31st Marine Expeditionary Unit are unable to surge—their transport aircraft are being torn down for foreign-object-debris inspections. The Abraham Lincoln strike group is stuck pierside. IndoPaCom can still fight, but without reinforcements, can it win? And if it cannot win, should it instigate a potentially larger conflict over a Chinese fait accompli when no American lives have been lost?
This scenario is, of course, fictional. But it is not unrealistic.
The Threat
Recent examples of asymmetric warfare—the 2020 Nagorno-Karabakh conflict, the 2022 invasion of Ukraine, and the 2023 Hamas assault on Israel—leave little doubt that small and medium-size drones on the battlefield are a real, dynamic, and increasingly dangerous threat to military operations.
The small unmanned aerial system (sUAS) quadcopter revolution took off in the early to mid-2010s, with the DJI Phantom largely responsible for introducing the consumer drone into the public consciousness. Not just toys for radio-control hobbyists, these sophisticated platforms can be piloted proficiently with a few hours’ practice and can provide commercial-grade aerial photography. With respect to the sUAS world, the introduction of auto-stabilized, GPS-capable multicopters is analogous to the shift in historical warfare from longbows to firearms.
Before long, commercial-off-the-shelf sUASs were being modified for nefarious purposes. Since at least 2014, terrorist organizations in the Middle East have been modifying sUASs to carry and drop improvised or repurposed explosive devices (such as mortar shells).1 These loitering munitions operate as armed surveillance: They provide a bird’s-eye view of the tactical situation using their onboard cameras but also can be used to attack targets or cover a retreat with their improvised weaponry.
Man-portable loitering munitions are not just improvised tools of nonstate actors, either—several countries have developed sophisticated, technologically advanced small loitering munitions, such as the Israeli Rotem-L and the U.S. Switchblade.
The U.S. military recognizes the threat these small drones pose on the battlefield. In 2016, the head of U.S. Special Operations Command, Army General Raymond Thomas, admitted his operators had been facing “an adaptive enemy who, for a time, enjoyed tactical superiority in the airspace under our conventional air superiority in the form of commercially available drones.”2 Speaking in 2021, former U.S. Central Command Commander Marine Corps General Kenneth McKenzie Jr. noted that “the growing threat posed by these systems . . . is the most concerning tactical development since the rise of the improvised explosive device in Iraq.”3 It is not often the U.S. military has admitted being at a technology-based tactical disadvantage, yet, as McKenzie continued, “We’re on the wrong side of the cost and position curve because this technology favors the attacker, not the defender.”4
The Strategic Context
The advantages that have made militarized sUASs useful in irregular warfare in the Middle East also lend to their application as part of a hybrid warfare strategy in great power competition.
China, which already uses hybrid warfare strategies proficiently, could greatly benefit from employing sUASs in a regional conflict. Using fishing trawlers as armed militia vessels in the South China Sea has allowed China to blockade islands and other maritime features to deny access to its regional competitors, while hiding behind plausible deniability—“they’re just angry fishermen”—and customary international law, which prohibits molestation of vessels solely conducting fishing operations.5
A combination of plausible deniability and legal protection is equally applicable to sUAS operations in the United States. Under 18 U.S.C. § 32 and 49 U.S.C. § 46502, destruction or disruption of a civil aircraft—including an sUAS—is a federal crime. The authority to disable or destroy sUASs in the U.S. National Airspace System is granted—with significant restrictions—to very few federal entities. The Department of Defense (DoD) exercises its authority to do so primarily in accordance with 10 U.S.C. § 130(i), which allows sUASs to be prosecuted if they threaten the “safety, security, or protection of [military] personnel, facilities, or assets.” Under these rules, U.S. military facilities in the homeland generally must determine hostile intent or actual violation of prohibited airspace to engage sUAS targets.
Furthermore, many Chinese-made and -programmed commercial sUASs are available inside the United States. DJI—the company that brought the world the Phantom—is by far the country’s largest supplier of commercial sUASs.6 Domestic consumers can go to their nearest large retailer and choose from a selection of DJI or other Chinese-manufactured sUASs, providing potential adversaries a variety of deniable platforms that could easily be weaponized.
The scalability of sUAS attacks also is advantageous to China’s use of hybrid warfare. There is no doubt a Chinese missile attack against Hawaii or San Diego would provoke an immediate and furious response; however, removing human casualties provides a gray-zone consideration for attackers and defenders alike. For example, although tensions rose in each case, the United States did not make an armed response to either the Iranian shootdown of an RQ-4 Global Hawk remotely piloted reconnaissance aircraft in 2019 or the 2023 Russian downing of an MQ-9 Reaper over the Black Sea. Although the combined cost of the aircraft was around $200 million, the United States did not consider either event a casus belli.7
In addition, given the close economic ties between the United States and China, the prospect of even limited war would be daunting, giving China the opportunity to take a plausible and politically acceptable off-ramp through diplomatic or economic concessions.
Playing Defense
The 2021 DoD Joint Counter-sUAS Strategy acknowledges that “a single successful strike on a high-value asset could affect Joint Force readiness by degrading the ability to project power and employ forces as needed,” yet it assesses the most likely malicious use of sUASs in the United States to be “collection of intelligence against U.S. forces and facilities.” While true, this statement may inadvertently downplay the likelihood of an armed strike. Designing defenses against the most likely versus the most dangerous threat, especially when each is plausible, would be a flawed solution.
The 2021 strategy is largely aspirational, delineating requirements to develop technology, equip and train the joint force, establish standards for counter-sUAS test and evaluation, and promulgate effective operational doctrine. These are all good courses of action, but their implementation in the domestic space is lagging.
The Department of the Navy, for example, staffs its counter-sUAS systems using shore-tour sailors, primarily fire-control specialists rotating off destroyers and cruisers, augmented by light-duty personnel. Many installations do not have enough assigned billets to support continuous watches on systems, while bases with extra sailors may poach them to fill auxiliary security force posts as gate guards. E-5 and E-6 supervisors run facility counter-sUAS programs with marginal oversight by base security officers. The lack of a dedicated training pipeline for these sailors has resulted in wide variability in doctrinal and technical proficiency. Sites have sent, at most, one or two sailors to vendor-led systems training, expecting them to pass that knowledge to their peers and replacements. Operator qualification is site specific, though a standardized Personnel Qualification System document is being developed.
Furthermore, the lack of a dedicated ashore counter-sUAS community has led to a servicewide gap in operational knowledge. Sailors assigned to counter-sUAS duty see it as career neutral or harmful, given it has little relevance to their ratings and that there are few senior enlisted billets to allow for advancement. Low funding prioritization for ashore counter-sUAS has led to maintenance and equipment deficits. The new robotics rating and a Joint Counter-sUAS University at Fort Sill promise to improve training and proficiency, but without a larger community and persistent body of knowledge, they will have a limited effect in the Navy.
The services also are increasingly faced with technical limits on their ability to counter the threat. The primary technologies used to defeat off-the-shelf and other sUASs are based on electronic detection and disruption of command-and-control datalinks. While modestly effective in countering surveillance, they still face several limitations.
First, detection depends on the system being able to recognize a given signal protocol. Novel control links must be characterized and incorporated into the systems to be detected, but this requires an initial observation; sUASs with new signal protocols potentially could be invulnerable until these links are characterized. Furthermore, the requirement to identify and characterize each link has led to wasteful duplication by the multiple vendors presenting tailored counter-sUAS solutions. As new sUASs increasingly use cellular network connections, they will become indistinguishable electronically from cell phones.
Second, precise geolocation of sUASs often is not possible with electronic detection alone. Many systems rely heavily on the ability to read the drone’s internal telemetry or the telemetry of the FAA-mandated remote ID broadcast. This information is relatively easy to falsify, however, as shown by Ukrainian efforts to defeat Russian use of DJI’s drone-detecting Aeroscope.8 Nontelemetry position calculation is possible using multilateration, but it is difficult and often unreliable. As the density of domestic sUAS operations increases, this method will become saturated with interference from surrounding targets.
Third, these systems’ ability to disrupt hostile sUASs is predicated on there being a control link to deny. Small UASs operating on preprogrammed flight paths are difficult to detect or counter because they may be radio silent. Even if a control signal is present, the sUAS may be preprogrammed to conduct contingency actions on loss of its link. The only reliable way to halt these aircraft electronically is to disrupt both the datalink and the drone’s internal navigation systems.
The limitations of radio detection and mitigation of sUAS targets are clear, but the solution is less so. Reliable detection of small drones will likely require tactical radar systems, and defeat options will need to include kinetic actions, such as drone-on-drone capture or other, more destructive methods. In both cases, these technologies will benefit from the use and continued development of automated target recognition processes as part of DoD’s larger efforts with artificial intelligence. The Replicator Initiative, introduced earlier last year, is a start, but it must be backed with the financial and political support to deliver the operational doctrine, technology, and required coordination with other federal entities to maintain a safe, secure National Airspace System. Part of this discussion also must refocus how sUAS threats are addressed by integrated air defense, as opposed to simply antiterrorism or law enforcement concerns.
Countering the small-drone threat in the homeland presents significant challenges to the joint force, especially the Air Force and Navy, and the threat will only continue to grow. Failing to adequately address it will provide dangerous opportunities to U.S. adversaries and make a successful domestic attack only a matter of time.
1. Thomas G. Pledger, “The Role of Drones in Future Terrorist Attacks,” Association of the United States Army, 3 March 2021.
2. Austin C. Doctor, “The Militant Drone Threat Is No Longer New. Why Does It Still Feel Novel?” Modern War Institute, 24 February 2022.
3. Gen Kenneth F. McKenzie Jr., USMC, and Gerald Feierstein, remarks at the Middle East Institute, U.S. Central Command, 8 February 2021.
4. McKenzie and Feierstein, remarks.
5. James Kraska and Michael Monti, “The Law of Naval Warfare and China’s Maritime Militia,” International Law Studies 91 (2015): 450–67.
6. Gina Chon, “DJI Is a More Elusive U.S. Target than Huawei,” Reuters, 17 December 2021.
7. Tara Law, “Iran Shoots Down U.S. Drone: What to Know about the RQ-4 Global Hawk,” Time, 21 June 2019; and Dan Rosenzweig-Ziff, “What Is the MQ-9 Reaper, the Drone That U.S. Says Was Hit,” The Washington Post, 14 March 2023.
8. Sam Skove, “How Ukraine Learned to Cloak Its Drones from Russian Surveillance,” C4ISRNet, 17 October 2022.
