The first use of an unmanned aerial explosive device was when the Austrian army deployed hundreds of balloons carrying explosives in their siege of Venice, which was fighting for independence against Austria. That was in 1849. Technology has moved on since then, but the use of drones has been a military tactic for longer than many realise. The British Royal Flying Corps used a radio-controlled aerial target for bombing practice in the First World War. By the Second World War, the first mass-produced drones appeared, the Radioplane OQ-2, used for reconnaissance by the US military.
Further drones were deployed in the 1950s and 1960s. Microelectronics and GPS navigation allowed the development of modern drones like the US Predator. This was initially used for reconnaissance in the 1990s and was later equipped with a Hellfire missile in 2001, allowing it to attack targets in Afghanistan, Iraq and beyond. These drones are operated remotely by human drone pilots, who may be located far away from the drone itself. A Reaper drone, the replacement for the Predator, can be controlled by its operator over a thousand miles away via satellite communication, can carry a payload of over 1,700 kg of missiles and bombs and fly for up to 27 hours. The Turkish Bayraktar TB-2 drone was used in the Nagorno-Karabakh conflict by Azerbaijan against Armenia in 2022. This drone uses artificial intelligence (AI) for takeoff and landing, target recognition and manoeuvring. It can autonomously return to base in emergencies.
The war in Ukraine has seen the use of drones on a massive scale, on land, sea and air. Aerial drones are used for reconnaissance as well as for dropping grenades and small bombs, while larger drones the size of small airplanes can be packed with explosives and flown remotely into targets. Both Russia and Ukraine use them, and the scale of production is huge. Ukraine aims to produce 4.5 million drones in 2025. Drones have transformed the battlefields in the Ukraine, constantly in the air and attacking anything that moves on the ground. Ukraine has used naval drones to sink Russian ships on multiple occasions. Ukrainian naval drones have even shot down Russian aircraft. Drone-on-drone combat is already a reality in the air. Back on the ground, drones are used for logistics and to retrieve wounded. They have even been used in combat, with one Russian unit reportedly surrendering to a unit of ground drones.
Electronic warfare is used to try to disable and block drones by jamming communication signals. One response has been the use of drones controlled by long fibre optic cables, but another is by using artificial intelligence. Drones with autonomous targeting can operate without needing to be in communication with human operators, and so can handle electronic jamming. The technology has civilian applications also, such as allowing delivery drones to deliver parcels despite unexpected weather conditions. Autonomous drones were used in the spectacular operation Spider Web. In this, Ukraine used drones delivered by trucks within Russia near airbases by unwitting Russian delivery drivers. At a pre-determined moment, the roofs of the trucks opened and released swarms of drones that targeted Russian warplanes on the airbases using terminal AI guidance. This means they could strike their targets despite Russian jamming. The cheap drones, each costing a few hundred dollars, were able to damage or destroy dozens of Russian warplanes, which each cost millions of dollars to build. Drones are becoming more and more autonomous, able to strike targets without the need for human operators, which raises obvious ethical implications and concerns. The ethics of such weapons have been debated at the United Nations. A coalition of non-governmental organisations was established as long ago as 2013 to lobby for a ban on lethal autonomous weapons.
Some fully autonomous weapons systems are already in use. The Phalanx air defence system is used on US ships for defence against close threats that approach the ship, such as missiles or aircraft. Essentially a guided Gatling gun, the Phalanx is usually operated by a human. However, if it detects more threats than the operator can manage, it can be switched to automatic mode, which allows it to engage multiple targets autonomously. According to the UN, a small 7.5kg Turkish drone system carried out an attack in Libya in 2020 autonomously, with no human in the loop. An Australian ground drone called the Jaeger-C, a sort of robotic mine, was demonstrated in 2022. AI navigation capabilities have already been developed for the US Reaper drone, and other autonomous drones have been demonstrated.
Such drones use a mix of AI techniques, from machine learning to computer vision to neural networks. These allow them to perceive their surroundings, avoid obstacles and detect targets. Local processing on the drones (“edge AI”) allows them to operate without the need for satellite communication and to remain operational even in a hostile electronic warfare environment, where radio signals are jammed.
Drone swarms are being developed that communicate with one another. Saab demonstrated a swarm of ten drones in a military exercise in March 2025. There have been displays of such swarms in synchronised drone shows in China involving hundreds of drones operating together. The largest demo so far, in Shenzen in 2024, involved over ten thousand coordinated drones. Although they have so far been shown as a benign light show, an alternative to fireworks displays, the military implications of such technology are obvious. Soldiers may be able to (sometimes) shoot down individual drones that are approaching them, but how will they deal with a coordinated swarm of hundreds? Artificial intelligence, as well as the economics of mass-produced cheap drones has transformed the battlefield in Ukraine. The Spiderweb operation, where cheap drones destroyed dozens of combat aircraft, had military planners around the world scrambling to consider whether such an operation could be carried out by a hostile party against them, either a nation state or well-organised terrorists. If such an attack occurred, what could be done to defend against it? Until recently, the idea of humans being hunted by autonomous robots has been the stuff of science fiction, such as the Metalhead episode of Black Mirror. The latest developments in the Ukraine war have shown that this prospect is much closer to reality than a futuristic fictional dystopia.
