The Perfect Can Wait: Good Solutions to the ‘Drone Swarm’ Problem


The nearly successful drone assassination attempt on Venezuelan President Nicolas Maduro earlier this month highlighted yet again a persistent worry for U.S. defense planners: the possibility that a swarm of cheap drone-borne bombs might overwhelm the sophisticated defenses a U.S. base or ship. While the defense industry has seized upon this concern and is currently at work developing new high-tech solutions to this problem, the Department of Defense can’t rely on those alone. It makes sense to develop such solutions, but the Department of Defense procurement process is long and the threat is now. With a little ingenuity, there is much that can be done with existing technology to defend effectively against drone threats. Accordingly, this article focuses on the measures the Department of Defense can employ now, with existing technology, to mitigate the threat of drone swarms.

The Current Problem

The drone swarm threat to U.S. naval installations and ships is already quite serious. Only a small amount of explosives and shrapnel would be required to cause significant damage to many of the most important radars, cameras, and important flight systems on ships, missiles, and aircraft. Damaging critical equipment would put military platforms out of action for several weeks or even months and put intense pressure on naval logistics chains and maintenance organizations at a time when they are already hard pressed to keep up with current demands. Even more importantly, such an attack orchestrated on a grand scale could leave U.S. forces unable to respond to critical events around the world in sufficient time to fulfill U.S. defense commitments to allies and friends.

Militaries are not defenseless when it comes to drone attacks. Conventional air defense technology proved itself capable of defense against light drone attacks at least twice this year in Syria. But, in a heavy assault involving hundreds of drones attacking simultaneously, traditional anti-aircraft defenses would probably be insufficient. Worse, defending installations near large population centers, to include most U.S. naval installations, presents an altogether different type of problem. The use of heavy anti-aircraft weapons in close proximity to civilian populations would present an unacceptable risk of civilian casualties

In March, WOTR contributor Lt. Col. David Pinion examined how to stay ahead of the swarm problem. Indeed, the defense sector has been hard at work for several years now developing a host of possible solutions, to include electronic warfare-focused systems like detectors and jammers, directed energy solutions such as high-intensity lasers, rocket propelled nets, and fully automated short range air defense systems.

The problem today, however, isn’t staying ahead of future threats. It is trying catch up with the current threat. The attempted assassination in Venezuela, even though unsuccessful, suggests that the U.S. military is already well behind the curve in adapting to this threat. Just as Maduro’s security detail was focused on land-based threats and lacked the tools, tactics, and procedures to defend against airborne drones, naval installations in particular have been similarly preoccupied with threats from the land and from the sea; airborne threats have up until recently been written off as the responsibility of the U.S. Air Force. The U.S. military may be developing great technological solutions but the modern Department of Defense acquisition system moves very slowly and fielding some of these purpose-built anti-drone systems will take years. Moreover, the high cost and logistical realities of some of these systems will make many of them inapplicable to medium- and lower-value targets.

The Current Solution

Fortunately, there are at least three fairly easy measures that can be adopted practically overnight to provide partial solutions to the problem at hand.

The first is to embrace one of the oldest and most underappreciated tools in the arsenal; the humble shotgun. Military planners often relegate the shotgun to the role of point defense and close quarters combat, but shotguns have been clearing the skies of low-flying, swiftly moving birds for hundreds of years. A well-aimed spread of birdshot is all it would take to turn that lethal quadcopter or other small drone into a tumbling mess of parts that will very likely do little damage at all. Firing shotguns into the air on a military base is certainly less than desirable, but it is an effective option and is preferable to filling the skies with the 5.56mm and 9mm rounds that security patrols are generally armed with today.

In order for this approach to be viable however, it is not enough that the weapons are available in the arsenal. By the time defenders are able to get to an armory and back out to the threat area, the attack will very likely have already occurred. Instead, by immediately implementing a defensive posture in U.S. bases around the world that emphasizes adding shotguns to the arsenal of the roving patrols and rapid response teams, defenders can provide serious improvements to base security overnight. By adding activities such as skeet shooting to the standard weapons training U.S. forces undergo, that defense will be improved significantly. A drone-specific shotgun shell, such as those currently under testing by the U.S. Air Force, would improve performance even further.

The second measure is to improve the communications between various security elements around our installations. The moment one part of the security team recognizes a drone threat, it should be rapidly relayed to the base police, security checkpoints, and especially the ships or aircraft personnel that are situated near the most likely targets. If security forces aren’t regularly training to respond to this type of attack as a team, they will be far less likely to combat it effectively.

Furthermore, base-wide communications need to adapt to be able to process threats more quickly and directly between the guards defending the base and the potential targets within the base. For example, most naval installations use a sort of hub and spoke model for defense, wherein each ship has its own command center which acts as intermediary to process information from its own respective guards, to communicate relevant data with other ships and the base police force, and pass critical information they receive back to their guards. While this level of control is effective in dealing with traditional land and sea-based threats, it is just too slow to adequately respond to a rapidly moving drone attack. Instead, key guards, such as the roving patrols that will ideally be armed with shotguns, need to have a direct line of communications with one another and base police that can be used for rapid threat coordination.

The third measure is to make the targeting problem more complicated for potential attackers. In current practice, the U.S. Navy relies on contracting companies to provide tug boat services to help move ships on and off their piers. Due to the high expense, the navy only pays for those services when they need to send a ship to sea or help it return to port. This is problematic because if anyone planning an attack learned the ship’s schedule, they would know the window of opportunity they have in which they could pre-load GPS coordinates and an approximate altitude into a drone so as to target specific equipment on a ship.

In the past, the U.S. Navy owned and operated its own tug boats, a practice which gave commanding officers much more leeway to move their ships into and out of port. It also had the side effect or shuffling up the locations of various ships around the port and, consequently, the locations of their critical equipment. If the navy were to return to such a system it would be much more difficult for potential attackers to rely on preset attack coordinates to attack ships in port. A similar tactic holds true on airbases, where aircraft are often exposed while parked near runways. Moving these aircraft with some degree of randomness would make them much harder to target as well.

As a result, attackers would instead have to rely more on complicated and expensive targeting systems or, more likely, direct control methods. If the operator is forced to directly control the drone, their command and control problem becomes much more difficult because they would need to have sufficient operators or sufficiently complex and expensive swarming technology to do so. The fundamental significance of a drone assault is in the asymmetry of a high-value target being defeated by a low-end threat. The higher the cost of the low-end threat for the attackers, the less asymmetry it presents and the less valuable a tool it becomes. By denying attackers access to fundamental operating plans such as GPS coordinate-based attacks, their targeting problem becomes significantly more difficult and the high-value target is correspondingly hardened.

Keep It Simple

The Department of Defense is right to invest in purpose built defensive systems that use networks of sensors and weapons to eliminate large numbers of small and rapidly moving drone threats. But when it comes to the use of drones in warfare, the cat is already out of the bag. As Paul Scharre noted in a 2015 article, “the enemy gets a vote on the future of swarming.” In truth, they get a lot of votes and one of the most important is when they choose to attack. While it may be hard to imagine any foreign power or group of powers coordinating a simultaneous strike on US military forces at home and abroad in the very near future, it is much less difficult to believe that hostile non-state actors might sponsor terrorist cells in the US with the aim of attacking vulnerable military and government targets. Such a group would have access to commercial drone technology more than sufficient to help them launch highly damaging attacks which would not only endanger the lives of armed forces personnel and or civilians, but could potentially hamper the U.S.’s ability to maintain its military commitments around the world.

When considering defense against high-tech attacks from hostile powers, the issue of readiness is even more critical. The Japanese success at Pearl Harbor, for example, was not simply due to the asymmetric effectiveness of air power against high-value surface targets. It also depended on catching the defending force totally off guard. A more comprehensive defense of Hawaii would have been preferable, but even marginal and readily available improvements in readiness such as better warning system management, torpedo nets, or anti-aircraft stations that were more consistently manned could have significantly reduced the effect of the attack.

This lesson is equally valuable today, because when it comes to the very real threat of a surprise attack involving swarming drones, the military can’t wait to have the perfect defense in place. It needs to adapt the tactics, training, procedures, and tools it has on hand to deal with or at least mitigate the damage of these threats even as they evolve.


Lt. Joseph Hanacek is a Surface Warfare Officer currently pursuing his masters degree in Systems Engineering Analysis at Naval ostgraduate School in Monterey, CA. He has previously served aboard USS Lake Champlain (CG-57) and USS Jackson (LCS-6). The views expressed here are not those of the US. Navy or any part of the U.S. government.

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