'When are the metal ones coming for me?'

Could robots really take over the world? Peter W Singer is an American political scientist who has written a book called Wired for War: The Robotics Revolution in the 21st Century.

Now out in the UK, the book explores the massively increasing role of robots on battlefields.

The book explores the questions that unmanned systems present for everything from when wars begin and end to warriors' very experiences – and the potential threat from AI to humans.

"You can't write a book about robots and war without have to deal with the 'when are the metal ones coming for me?' question," says Singer, who was also coordinator of defence policy for Barrack Obama's Presidential campaign.

But isn't it tempting to think of military robotics as being something of the future rather than the present? "Exactly! That is the point of the book, to capture this immense revolution around us that we aren't much noticing. Look at the raw numbers. When US forces went into Iraq in 2003, they had zero robotic units on the ground. By the end of 2004, the number was up to 150. Today it is over 12,000."

With the increase in drone strikes into Pakistan, as well as the expanded purchasing and use of unmanned systems in the UK's new defence plan, Singer believes that the subject matter of the book is becoming even more timely than ever.

"Already in the prototype stage are varieties of unmanned weapons and exotic technologies, from automated machine guns and robotic doctors to tiny but lethal robots the size of insects, which often look like they are straight out of the wildest science fiction," explains Singer.

For his book, Singer interviewed hundreds of robot scientists, science fiction writers, soldiers, insurgents, politicians, lawyers, journalists, and human rights activists from around the world.

Singer did meet some people he refers to as "refuseniks," such as scientist Illah Nourbakhsh. "Illah is one of the most fascinating people I met in the journey. They are robotic scientists who look at what happened to the nuclear physicists behind the Manhattan Project that built the atomic bomb and then regretted it for the rest of their lives.

• Book extract: The refuseniks – roboticists who just say no

"The Refuseniks like Illah don't want the same thing to happen to them and instead want to push a debate about ethics and robotics, including the ethics of the scientists who build them. So, despite the huge amount of money being offered, he refuses to take Pentagon funding and instead builds robots that he believes will make the best possible contribution to society."

Moore's Law in robotics

So how will robotic technology develop? Singer believes the two trends to keep an eye on are Moore's Law and miniaturisation.

"The multiplying effect of Moore's Law, year after year, is the reason that refrigerator magnets which play Christmas jingles now have more computing power than the entire Royal Air Force did back in 1959.

"If Moore's Law holds true, then within 25 years, this doubling effect will have robots running on computers that are a billion times more powerful than those today.

"To be clear, I don't mean "billion" is the sort of amorphous way that people throw about the term, but literally multiplying the power of an iPhone or Predator drone by 1,000,000,000.

"Now some argue that Moore's law won't hold and it will slow down. That may be true. But let's say the pace of advancement only goes one percent as fast as it has for the last few decades. Then our robots will be guided by computers a mere 1,000,000 times more powerful than today," muses Singer.

And what about miniaturisation, how will that evolve? "I recall seeing at one Air Force lab a tiny rocket engine that fit on the tip of a pen. Imagine the capabilities that can provide in war! A commando will literally fly a 'fly on the wall' in from over 1000 meters away.

"But what the book is about is also how we have to weigh the dilemmas that very same technology will bring. For instance, that the very same technology will be available to terrorists, corporations, criminals, and even my neighbours."

So Singer believes we have to better understand what is happening now if we want to handle it intelligently. "Robotics and AI is no longer just science fiction, but becoming technologic, as well as political reality. Or as one US military-funded robotics researcher put it to me, many may want to "think that the technology is so far in the future that we'll all be dead [and so don't have to talk about it]. But to think that way is to be brain dead now."