Islamic State (IS) has used aerial drones for reconnaissance and battlefield intelligence in Iraq and Syria and has attempted to use aerial and ground drones with explosive payloads to attack Kurdish troops. IS-directed or -inspired attacks in Australia, Canada, Denmark, the United States and France and failed or foiled attacks elsewhere, including the United Kingdom, have demonstrated the group’s desire to attack targets outside the Middle East. Given that threat is a function of capability and intent, should we therefore be concerned about the possibility of Islamic State or another terrorist group using drones to attack Western cities? A recent report from the Remote Control project and Open Briefing examined this scenario, among others.
The Drone Threat
For Hostile drones, the Open Briefing team assessed the capabilities of over 200 commercial and consumer/hobbyist drones capable of operating in the air, on the ground or on or under the sea. Although limited at present, they found that there are consumer drones available today that are capable of delivering an explosive payload equivalent to a pipe bomb (1-4 kilograms) or a suicide vest (4-10 kilograms). Many more could be modified with readily-available components to increase their stated payload capacity. If used in a swarm against the crowd at a major sporting event, for example, they would cause serious injury and multiple fatalities. If one or more of the drones carried on-board cameras to record the event, it would also provide a group such as Islamic State with prime propaganda material.
Using drones for terrorist attacks has several advantages over conventional methods, including removing the need to convince a suicide bomber to carry out an attack and opening up targets a bomber would not usually be able to access due to security. An attacker would not even necessarily need to weaponise a drone, as the vehicle itself could be used as a projectile to target a light aircraft’s engines on take-off or landing, for example. In addition to attack, Open Briefing identified intelligence gathering as another major capability that drones offer terrorists or insurgents, as demonstrated by Hezbollah, Hamas and Donetsk separatists. For example, Donetsk People’s Republic militias reportedly possess and deploy sophisticated Russian-made Eleron-3SV drones for intelligence, surveillance and reconnaissance (ISR) in eastern Ukraine. Drones provide insurgent groups with an excellent level of battlefield awareness and provide terrorist groups the ability to reconnoitre a target before an attack These same capabilities are also of interest to criminal, corporate and activist threat groups. For example, aerial drones have been used to transport illicit drugs over the Mexico-US border and in April 2015 a man protesting over the Japanese government’s nuclear energy policy landed a drone containing radioactive sand on the roof of the prime minister’s office in Tokyo.
The same technology Western militaries have been controversially employing to target terrorists in Afghanistan, Pakistan, Yemen, Iraq and elsewhere for years is now being used by various threat groups to target Western interests. This is a prime example of how the tactics and technologies of remote-control warfare have created unintended consequences for those countries that have embraced them.
Towards Drone Countermeasures
No single countermeasure is completely effective at limiting the hostile use of drones by non-state actors. Open Briefing therefore proposes the United Kingdom adopt a hierarchy of countermeasures encompassing regulatory, passive and active countermeasures, which provides a layered defence. Regulatory countermeasures include point of sale regulations, civil aviation rules and manufacturing standards and restrictions. Passive countermeasures include early warning systems and signal jamming. Active countermeasures include kinetic defence systems, such as missiles, rockets and bullets, and less-lethal systems, such as projectile weapons and net guns. Each stage of the hierarchy of countermeasures requires government action, but it is the regulatory countermeasures upon which it can affect the greatest change.
Any changes to the laws surrounding the use of drones need to be proportionate to the risks and balance interests relating to privacy, individual freedoms, safety and commercial interest. In addition to the existing regulations around drones needing to be flown within visual line of sight, below 400 feet and not within 50 metres or a person, vehicle or building, there have been calls from airline pilots and politicians for a registration scheme for consumer drones and for the adoption of firmware limitations that restrict the ability of drones to travel near geofenced no fly zones around sensitive sites, such as airports or nuclear power stations. These are reasonable demands that should be implemented as soon as possible.
However, these regulations may have limited impact beyond reducing accidental incidents. Unless coupled with some kind of identification/tracking technology built in to drones, a registration scheme would not remove consumer drones from the terrorist arsenal altogether (in any case, such technology would be a step too far in terms of state surveillance and could be easily disabled). What registration would do is impose some control on a presently uncontrolled market and impress upon drone operators the responsibility they must take for their actions. It may also reduce the supply of readily-available drones that could be used for nefarious purposes. In the case of geofenced no fly zones, those wishing to carry out an intentional attack could still purchase open-source controllers that can bypass geofencing, and inertial navigation systems (using dead reckoning) would allow a drone to continue to a static target with reasonable accuracy even if it were possible to jam controller frequencies and GPS signals within the target perimeter. What geofencing would allow is for security to assume that any drone operating within the no fly zone is unauthorised and potentially hostile, allowing them to react appropriately (evacuation and/or deploying active defences).
There are two further regulations that have received little attention but which should also be considered. Firstly, the payload capacity of the consumer drones available for purchase or import in the United Kingdom without licence should be legally limited to that reasonably required to carry a camera and nothing else. This would mean these types of drones could not be used to carry explosive payloads without further modification. Secondly, owners of commercial drones capable of carrying heavier payloads for legitimate reasons (such as in agriculture or search and rescue) should be legally required to store them securely (in the same way fertiliser must be appropriately secured to prevent its use in homemade bombs, for example). This would prevent the theft and use of drones capable of carrying considerable explosive payloads by terrorists and other threat groups.
A Layered Defence
The current regulatory regime around drones in the United Kingdom is very limited. The adoption of the four regulations outlined above would balance the various interests and address specific risks without being unduly restrictive. However, regulations are not a panacea – they would merely limit the ability of terrorists and others to acquire drones with the capabilities needed for attack or intelligence gathering. That is why the government must also work with the police, security services and industry to explore the passive and active countermeasures that are needed to protect VIPs or sensitive sites and ensure that procurement and R&D funding is made available to purchase or develop the required systems. This should include the development of less-lethal systems for destroying or disabling hostile drones in urban environments, where little warning of an attack and the risk of collateral damage limits the usefulness of conventional kinetic countermeasures, such as missiles or bullets. Again, though, this will not be a panacea: the less-lethal systems currently available are of limited effectiveness against one or more fast-moving, small drones. As with all the possible countermeasures, such systems – if coupled with early-warning – would form part of an effective layered defence.
Ultimately, the regulations and technology needed to reduce the threat from the hostile use of drones are either available now or are under development. The British government has to act now to bring drone regulations up to date and invest in the technologies needed to keep us safe. In the meantime, the threat from the malicious use of civilian drones is only going to increase.
Chris Abbott is the founder and executive director of Open Briefing (www.openbriefing.org). Matthew Clarke is an associate researcher at Open Briefing. Hostile drones: The hostile use of drones by non-state actors against British targets was published by the Remote Control project on 11 January 2016.