The world's first glimpse of a killer drone in action was over the English Channel: a Royal Navy patrol boat reported "a bright horizontal flame" in the sky. The device emitting the flame had stubby wings and was shaped like a rocket, and was travelling from the French coast at more than 200mph. Too small and too fast to be intercepted, it arrived in England's Home Counties without warning; as it plunged earthwards the low drone of the motor cut out and there were three seconds of silence before the massive explosion. Where it exploded, the human beings at the epicentre simply disappeared, vaporised.

Of course, for all the similarities, this was not a Reaper or a Predator, the Unmanned Aerial Vehicles (UAV) used in action by British and US militaries today. The most glaring difference is that modern drones don't self-destruct, except by mistake. This was the Vergeltungswaffe, the V-1, known affectionately to its German makers as the Maybug and to its terrorised British targets as the "doodlebug". The Nazis had experimented with making it radio-controlled, but in the end its navigation system was crude. Yet this PAC (pilotless aircraft) – Hitler's last, desperate throw of the dice as the Allies swarmed towards Berlin – marked the start of a new era in warfare as decisively as did "Fat Man" and "Little Boy", which plummeted towards Hiroshima and Nagasaki a few months later.

The Predator and the Reaper and their rivals and relatives, some developed at Cranfield Aerospace ("Innovation at its Best") in Bedford, are crucially different from the Maybug because they target their victims so precisely. The 186 men, women and children vaporised by a doodlebug in the New Cross branch of Woolworth's in London's East End one November Saturday in 1944 had no idea what was coming their way, and no reason to feel more than normally apprehensive. By contrast, many of the intended victims of today's drones experience the very specific fear of being killed by them. In US Department of Defense videos with titles such as "UAV Kills Heavily Armed Criminals" and posted on YouTube, the visceral terror of the turbaned figures about to die is palpable. (Drone pilots call the moment of the kill a "bug splat" because of the way it looks on their screens.)

For what the US authorities call "personality strikes" – high-value targets – that specific fear can last for months, even years. Friends and relatives of the Islamist militant and US citizen Anwar al-Awlaki had such strong grounds to fear his assassination by drone that the American Civil Liberties Union filed a lawsuit in August 2010 on behalf of his father, Nasser al-Awlaki, to try to stop it happening. The judge eventually dismissed the case, arguing that Nasser al-Awlaki would have no grounds to pursue it unless and until his son was actually killed. And so it came to pass: on 30 September 2011 in southern Yemen, the bearded American became one of at least four US citizens, to date, to be deliberately assassinated by US drones.

Nearly 70 years after the doodlebug, the pilotless aircraft was now fully out of the arms dealers' closet. The cruel and extra-legal targeting of al-Awlaki for liquidation over a number of years, the futile attempt to get the American courts to stop it, and then the coup de grâce in the deserts of Yemen removed the last shreds of official deniability from the killer drone programme – and nobody gave a damn. As one White House official told Rolling Stone magazine, "If Anwar al-Awlaki is your poster boy for why we shouldn't do drone strikes, good fucking luck."

As a basic idea it is childishly simple, and many of us once played with them: a miniature plane you can pilot remotely. The only real difference is the sophistication of the vehicle itself, and of the navigation and piloting systems.

Drones in service or development today range from a giant with a 400ft wingspan, intended to cruise non-stop for five years, to tiny microdrones powered by miniature batteries; some are the size of a Boeing 727, while the Predators and Reapers in use in Afghanistan are comparable in size to model aircraft. But whatever their shape or size, all of them are designed for one of two purposes: spying or killing.

Even some very sophisticated modern drones look like toys, being scarcely bigger and no less simple and clumsy to launch. Like the toys we played with, you can build a drone at home. One of the people who recently did so was Francis Fukuyama, the Japanese-American political scientist most famous for coining the phrase "The End of History" to describe the global situation after the collapse of the Soviet Union. "For the past couple of months I have been building myself a surveillance drone," he wrote recently in the Financial Times. There is a funny video that can be tracked down online of him flying it in Hoover Park, Palo Alto, California, near where he teaches at Stanford University.

The drone he built is a geek's delight, "a remotely controlled quadcopter", as he explained, "a small helicopter with four rotor blades that looks like a flying X, with an onboard video camera that sends a live feed back to my laptop base station ... In future I plan to equip the aircraft with an autopilot system that will allow it to fly from one GPS-specified location to another without my having to pilot it."

Enraptured by the technology, Fukuyama worries about what a world full of the things will feel like. "A world in which people can be routinely and anonymously targeted by unseen enemies," he writes, "is not pleasant to contemplate." For all the technological refinements, the device in Fukuyama's video, hovering uncertainly over Hoover Park's balding turf and eyeing speculatively both the senior Stanford fellow with the joystick, gazing skywards, and the odd dog-walker, does not seem a million miles from the sort of thing you used to be able to buy in a box at the local toy shop and stick together with UHU. And it's that – the conceptual simplicity yoked to ever-increasing technological refinement – that has propelled the drone into headlines across the world in the past year. It is at once a fiendishly efficient killing machine, the ultimate spy weapon, and a tool of potentially vast utility to police forces, farmers, estate agents and journalists.

Needless to say, it is in the US that the possibilities are being most energetically explored. Rural Louisiana has a problem with feral pigs, which breed rapidly and root up farmers' crops: new state rules are planned to permit their year-round hunting. Last year an electrical engineer called Cy Brown, in the Louisiana town of Bunkie, devised a labour-saving approach to the problem. Equipping a model plane with a heat-sensing camera, he sends the "Dehogaflier", as he calls it, up over his brother's rice farm and the craft sends images of the pigs back to a computer on the ground, enabling hunters to locate them and head to the spot to shoot them. "In 15 minutes you know if it's worth going out or not," Brown said.

If feral pig hunters can find a use for such devices, so can many other people: often it is the courts more than the technology that set the limits, and a law signed by President Obama in February prevents the Federal Aviation Administration from stopping the use of drones for many commercial purposes. For a real-estate agent to seduce potential clients with aerial movies of his most expensive properties would, until recently, have required a camera crew, a full-sized helicopter and a Hollywood-sized budget to pull off; but now that the strict rules controlling private use of the skies have been rolled back, it can be done for next to nothing, by a drone equipped with a camera. Other uses already in the planning stage include crop dusting, monitoring oil spills and wildlife, and surveying damage from natural disasters.

Drone boosters are keen to accentuate the positive: the drone can be the compassionate hand of society, they point out, reaching into areas and completing tasks unthinkable until now. Steven Gitlin, a spokesman for AeroVironment, a California-based drone manufacturer, spelled out some of the possibilities of drone use for police forces. "Think of a toddler wandering away from home, or an elderly per

son with Alzheimer's wandering off in a city," he said. "Think of an office hostage situation where exits and entrances need to be watched, or a hazardous-material incident at a chemical plant where it's too dangerous to send in people. Think of traffic accidents. How useful would it be to have a system that can fly 100ft above and piece together a picture of what happened? These systems can be kept in the trunk of a car and deployed in five minutes."

The use of drones for the surveillance purposes sketched by Gitlin takes us back to their original function. The critical weakness of the Nazi doodlebug was the lack of control: its only use was as a mechanical kamikaze. Once you had control of the thing, everything changed. George Orwell was the first to describe the possibilities, in his novel 1984. "In the far distance a helicopter skimmed down between the roofs, hovered for an instant like a bluebottle, and dashed away again with a curving flight," he wrote in the novel's first chapter. "It was the police patrol, snooping into people's windows..."

The technology was not all that far behind him. The first drones capable of subtly controlled movement were a spin-off from the Cold War space race. By the time the US was fighting in Vietnam, the utility of the new devices had become plain. "Vietnam was decisive to the development of drones as the perfect tools to perform dangerous missions without the risk of losing a pilot," according to aviation historian David Cenciotti. By the time America pulled out, their drones had flown some 3,500 ISR – intelligence, surveillance and reconnaissance – missions.

It is the snooping function foreseen by Orwell that is the most significant next step for drones in our societies: with our cities and public buildings already saturated with surveillance cameras, we may fondly suppose that the state's monitoring of our daily lives has gone as far as it can go. But we ain't seen nothing yet.

We find ourselves today at a bizarre interface between the imminent new reality and the most paranoid of science-fiction fantasies. In the turbid realms of UFO and ET "research", the flying saucer and its derivatives have finally been put out to grass, along with the little green men who inhabited them. Enter in their place, in a blinding blaze of fancy, the "dragonfly drone", a machine that might have been inspired by a Leonardo da Vinci sketch, covered with mysterious "extraterrestrial" lettering that bears a strong resemblance to the Japanese katakana syllabary. In June 2007 in Alabama, it was reported, "the mystery of the dragonfly-shaped aerial drones took another turn with the release of an alleged secret report containing photographs of alleged extraterrestrial technologies". The basic idea is that US authorities over the years recovered the debris of crashed dragonfly drones from outer space and then tried to retro-engineer them (including crucially their "anti-gravity generator") for commercial use.

But being an ET-oriented futurist visionary is a losers' game these days: all their extravagant fancies keep getting mugged by the real stuff coming out of the research laboratories. "It was way back in May 2010 that I first spotted the flying drones that will take over the world," Farhad Manjoo wrote in Slate magazine earlier this year. In a video shot in a robotics lab in the University of Pennsylvania, "an insect-like, laptop-sized 'quadrotor' performs a series of increasingly difficult tricks," he wrote. "The drone can fly through or around pretty much any obstacle. We see it dance through an open window with fewer than three inches of clearance... it pirouettes in an ellipse. It gets a claw-like gripper that allows it to pick up objects, and then it learns to 'co-operate' with other drones and pick things up together." The tiny drones fly through obstacles, land clumsily and recover, get together in a team to build structures, flying in a coordinated ballet.

This is the latest and perhaps most hair-raising development: "They're built," Manjoo writes, "to automatically, instantly collaborate in the air. The behaviour is modelled after insects like ants – it happens without a central coordinator, via the drones' ability to sense their distance from one another as they fly. By the time you've stopped staring [at the video]," Manjoo comments, "you've opened another browser tab to look for good deals on bomb shelters."

Orwell's black vision of total surveillance – "It was even conceivable," he wrote in 1984, "that [the Thought Police] watched everybody all the time" – is finally achieving its technological apotheosis. In a few weeks, the US Army is expected to deploy in Afghanistan its latest helicopter-style drone, the A160 Hummingbird, equipped with 1.8 gigapixel colour cameras. Able to hover, unlike current drones, it will have "unprecedented capability to track and monitor activity on the ground", the Army says. Able to track people and vehicles from above 20,000ft, and with a 65sq-mile field of view, it will have 65 steerable "windows" able to follow separate targets. More modest surveillance drones may be used to enhance police monitoring of London's Olympics.

As with the development of earlier awesome technologies, such as the atom bomb, there is a temptation with drones simply to gape, to confess amazement and admit impotence to halt the march of "progress", no matter where and upon what it should trample. But unlike developments in purely speculative, futuristic fields, that luxury is barred to us with drones. Because we already see how their combination of miniature scale, total controllability and long-range impunity and deniability have proved irresistible to a handful of very powerful governments. Just three, in fact: the US, Israel and Britain.

he first major use of killer drones by the US was when Predators attacked a convoy in Yemen in 2002, killing the al-Qa'ida leader in the country. Since then, particularly in Iraq and Afghanistan, their use has increased exponentially: the US is now believed to have 19,000 Predator and Reaper drones in war theatres; Britain's Reaper drones have carried out 200 strikes in Afghanistan, 3,000 alleged terrorists are said to have been killed by them, along with many hundreds of non-terrorists unlucky enough to have been in the way. And President Obama has proved a big fan of drones: in his name the US has made 200 drone strikes on Pakistan, compared to 44 ordered by his predecessor; under George W Bush around 400 died in such strikes, while under Obama the number is believed to be around 1,600. His expanded use of the devices, despite the obvious and glaring moral issues that remote-control murder poses, has proved politically canny: their use has attracted a derisory amount of criticism, either here or in the US.

With the news that Britain's Reaper drones would, from now on, be remotely piloted not from Nevada but from a new installation inside RAF Waddington in Lincolnshire, a retired midwife called Helen John, one of the pioneers of the legendary Greenham Common anti-cruise missile campaign, set up shop outside the base to protest, as reported in the Lincolnshire Echo. It was notable, however, that this time around, the 73-year-old was completely alone.

Chris Cole, a veteran pacifist campaigner based in Oxford, has welded together a network of groups to raise awareness of and direct criticism at military drone programmes. In the US, the debate in magazines such as Slate and, most recently, Rolling Stone has been lively and high-profile. But in neither Britain nor the US have the protesters yet succeeded in making their voices heard over the silence of the politicians and the snores of the majority.

The reason is not hard to find. Drones allow the US to kill "bad guys" in countries such as Somalia and Yemen and Pakistan where no US troops are committed. And at the same time they ensure that these obscure, undeclared battlefields yield no body bags to trouble the sleep of America. That's no doubt why US Defence Secretary Leon Panetta has called drones, "the only game in town".

They will doubtless continue to enjoy a large degree of impunity in our mass media, either until a lot of people come to see the ordinary inhabitants of places such as Pakistan's North West Frontier as human beings who deserve to be left in peace; or (and this is likely to happen sooner) some of our nastier enemies get hold of similarly terrifying technology and start to use it. Then, and the day cannot be far away, we will suddenly see the other side of the story.

No pilot necessary: The stealthy rise of Unmanned Aerial Vehicles

In 2004, US drones in Afghanistan and Iraq flew five patrols per day. In 2011, the figure was 54 per day

The AeroVironment RQ-11 drone used by the US military, about the size of a hobby remote-control plane, costs $35,000. Predators and Reapers are said to cost $13m each

The US-dominated market for drones is valued at $5.9bn. It is expected to double in value within a decade

The UK has six Reaper MQ-9 drones, and is spending £135m to expand the fleet size to 10. The UK is the only country besides the US and Israel to have drone military capability

The Reaper can carry 14 Hellfire missiles, cruise at 170 knots, and stay aloft for 14 hours

Of the 700 to 1,000 people killed by drones in Pakistan since 2006, about 31 per cent are thought to have been civilians