Ever-more advanced drones capable of carrying sophisticated imaging equipment and significant payloads are readily available to the civilian market.
Unmanned aerial vehicles (UAVs) currently present the greatest risk because of their capabilities and widespread availability, but developments in unmanned ground (UGVs) and marine vehicles (UMVs) are opening up new avenues for hostile groups to exploit.
A range of terrorist, insurgent, criminal, corporate and activist threat groups have already demonstrated the ability to use civilian drones for attacks and intelligence gathering. The best defence against the hostile use of drones is to employ a hierarchy of countermeasures encompassing regulatory countermeasures, passive countermeasures and active countermeasures.
Regulatory countermeasures can restrict the capabilities of commercially available drones and limit the ability of hostile groups and individuals to procure and fly drones. Policymakers should pass stricter regulations limiting the capabilities of commercially available drones in the key specifications affecting hostile drone operations, particularly payload capacity. Particular attention should be paid to limiting the attack and ISR capabilities of UAVs and the attack capabilities of surface UMVs. Manufacturers should be required to install firmware that includes the GPS coordinates of no-fly zones around sensitive fixed locations. Finally, civilian operators of drones capable of carrying payloads should be licenced and the serial numbers of purchased drones registered.
Passive countermeasures alert security to the presence of any drone within a no-fly zone or defensive perimeter around a static or mobile target. They limit the ability of hostile groups and individuals to guide a drone onto a mobile target or target of opportunity or take evasive action against any kinetic defences. The British government should support the research and development of commercial multi-sensor systems capable of detecting and tracking drones within a target area. The government should also make funding available to police forces and specialist units for the purchase of early warning systems and other passive drone countermeasures, including radio frequency jammers and GPS jammers. The government should also relax the regulations restricting the use of radio frequency jammers for protection against hostile drone use around defined key sites.
Active countermeasures can be deployed against drones that still represent a threat despite passive systems being employed. However, the active countermeasures currently available for use in non-military settings are limited. The British government should support the research and development of innovative less-lethal anti-drone systems, such as directional radio frequency jammers, lasers and malware, and set out clear guidelines for the police and military use of kinetic weapons against hostile drones as a last line of defence.
However, such countermeasures are not foolproof. Furthermore, there is also the very real chance that, as with drones themselves, countermeasures will be deployed in turn by some threat groups against British police or military drones. The technology of remote-control warfare is impossible to control; the ultimate defence is to address the root drivers of the threat in the first place.
A supplementary risk assessment is also available.