The unmanned aerial vehicle (UAV hereafter), colloquially known as the ‘drone’, can be both a sword and a shield to all belligerents. The unarmed surveillance drone can provide advance warning of a strike. An armed drone can deliver a strike whilst service personnel are miles away in safety. These devices can be either highly sophisticated, like Predator drones, or a device of the most basic form. The availability of drones to the consumer place them within the reach of non-state actors. In January 2018, the Russian Defence Ministry complained that ten UAVs had descended on Khmeimim air base in the Lataki province of Syria. Another three attacked the nearby Russian naval base at Tartus. The source is unidentified at this stage but it is thought to be the first drone strike of its magnitude by terrorists.

Automated devices may well be the future of legitimate warfare. They can help load aircraft, repair machinery, deliver supplies and gather intelligence. But the UAV is controversial. The perception of the public is one of armed killer drone bots and phalanxes of robotic hoplites replacing the thinking soldier, with the loss of critical ethical and moral cognition. Drones do raise ethical questions and therefore legal issues, but a solution must be found if the full potential of this technology is to be realised.

Forms of remote aggression

Remote aggression has been preferred for many years over direct confrontational combat. This is not primarily a debate over combat systems. Autonomous armed weapons are still a way off and the infantry need not fear for their future. However, the UK does have a much more automated military than hitherto and this is likely to increase. UAVs perform many roles and have clear advantages over piloted vehicles; they save human labour and protect service personnel from risk.

UAVs can take many forms. There are over a thousand makes and models of UAV on the market or in development and range from micro UAVs that fit into the palm of a hand to turbo jets. A UAV is simply an aircraft that can be either piloted remotely or operated autonomously. They can be either benign or armed. The legal issues have generally concerned the use of armed drones but, in fact, UAVs have been used widely for many years for reconnaissance and surveillance. More recently they have been used for aggressive ends. During the Vietnam War unarmed drones flew more thee thousand reconnaissance flights, some equipped with Maverick air to ground missiles. In 1993, during the conflict within the former Yugoslavia, the Predator drone was deployed. Most drones are not weaponised. In 2014, less than 1% of US operated drones carried operational weapon systems. The UK operates five types of UAVs. The RAF operates Reaper, the Army operates Watchkeeper, Desert Hawk III and Black Hornet, and the Navy operates Scan Eagle. Only the Reaper system can be armed and conduct air strikes. Nevertheless, the use of armed drones can only increase.

Drones clearly have advantages over manned aircraft, in particular for intelligence purposes. They can gather photographic intelligence from areas that could not be reached by manned aircraft. They carry no danger to pilots either of injury, death or capture. Some drones also have a much greater loiter time than manned aircraft, being generally lighter. Equally, manned aircraft has greater speed and field of vision than a drone which is limited to the view of its sensors, and are generally less affected by weather conditions. The use of unarmed drones is established and unremarkable. The controversy lies with the armed drone.

The law of armed conflict

Armed drone strikes do blur the boundaries of the battlefield. There is no prohibition upon the use of remotely controlled weapon systems per se. Clearly, nothing could be placed on a UAV that could not be carried by a manned aircraft. The fact of automation does not change an unlawful weapon, like cluster munitions, into a lawful one. The basic principles of humanity, proportionality and distinction are no more complicated for remotely piloted aircraft than manned ones. The issues to which UAVs give rise are more subtle than that.

Historically, operations would be confined to a battlespace and would be conducted by military personnel. It would be fairly clear what is or is not a legitimate objective and who was responsible for any strike. The use of aggression in these circumstances is regulated by the law of armed conflict (hereafter LOAC). This provides for strikes against combatants and those directly engaged in hostilities and tolerates proportionate collateral damage to civilians that is in pursuit of a military necessity.

The remote use of aggression by a person outside of the conflict zone is more opaque. There is no dispute that UK based service personnel who operated armed drones that released weapons within battlespace and targeting combatants would be covered by LOAC. A strike upon a person who lacked the status of a combatant but was a direct participant to the hostilities would be harder to judge. Such an action would only be lawful if the target were in the course of direct action at the time of impact which would be harder to judge remotely. Moreover, not all operators are military personnel. We know that the US relies on the CIA to conduct an armed drone program which is manned by civilians. There is no prohibition upon this in international humanitarian law or beyond but it does change the status of the operator. Such civilians cannot enjoy the protected status of a belligerent. Indeed, they could well become direct participants to the hostilities with all that implies. This would not only cover a civilian who launches an attack from an armed drone. It would also apply to a civilian who passed information to ground forces for the purposes of launching an attack and there is no need for immediacy. Such a person may well not have the protections of a combatant such as prisoner of war status and combatant immunity upon war’s end.

Further, accountability may be harder to determine. An aircraft system may be either controlled, pre-programmed by the crew, or fully autonomous. Even with fully autonomous systems, it would be unrealistic to think that humans have no responsibility. An autonomous system is a device like any other: designed, manufactured, and programmed by a human being. However, it may be difficult to allocate responsibility to a particular person. An infanteer who commits war crimes will be easy to identify and will face the consequences himself. Identifying accountability for a weapons system will not be so simple. Remotely piloted vehicles are commanded by their operator and LOAC presumes they have ultimate control. This begs the question of who would be to blame for devices that malfunction. With fully autonomous systems there would be no operator in control, and the designer and programmer, who might both be civilians, could have more control over what the UAV actually does than the person who switches it on.

An ever increasingly automated society will evolve to have an increasingly automated military. This creates no difficulties per se. Remotely operated items have many advantages from the point of view of cost and safety. However, these legal issues must be considered and resolved at a speed that matches the onward march of technology.

Contributors Jo Morris and Libby Anderson of Charter Chambers