But humans still make the decision to fire, and in the case of CIA strikes in Pakistan, that call rests with the director of the agency. In future operations, if drones are deployed against a sophisticated enemy, there may be much less time for deliberation and a greater need for machines that can function on their own.
The U.S. military has begun to grapple with the implications of emerging technologies.
“Authorizing a machine to make lethal combat decisions is contingent upon political and military leaders resolving legal and ethical questions,” according to an Air Force treatise called Unmanned Aircraft Systems Flight Plan 2009-2047. “These include the appropriateness of machines having this ability, under what circumstances it should be employed, where responsibility for mistakes lies and what limitations should be placed upon the autonomy of such systems.”
In the future, micro-drones will reconnoiter tunnels and buildings, robotic mules will haul equipment and mobile systems will retrieve the wounded while under fire. Technology will save lives. But the trajectory of military research has led to calls for an arms-control regime to forestall any possibility that autonomous systems could target humans.
In Berlin last year, a group of robotic engineers, philosophers and human rights activists formed the International Committee for Robot Arms Control (ICRAC) and said such technologies might tempt policymakers to think war can be less bloody.
Some experts also worry that hostile states or terrorist organizations could hack robotic systems and redirect them. Malfunctions also are a problem: In South Africa in 2007, a semiautonomous cannon fatally shot nine friendly soldiers.
The ICRAC would like to see an international treaty, such as the one banning antipersonnel mines, that would outlaw some autonomous lethal machines. Such an agreement could still allow automated antimissile systems.
“The question is whether systems are capable of discrimination,” said Peter Asaro, a founder of the ICRAC and a professor at the New School in New York who teaches a course on digital war. “The good technology is far off, but technology that doesn’t work well is already out there. The worry is that these systems are going to be pushed out too soon, and they make a lot of mistakes, and those mistakes are going to be atrocities.”
Research into autonomy, some of it classified, is racing ahead at universities and research centers in the United States, and that effort is beginning to be replicated in other countries, particularly China.
“Lethal autonomy is inevitable,” said Ronald C. Arkin, the author of “Governing Lethal Behavior in Autonomous Robots,” a study that was funded by the Army Research Office.
Arkin believes it is possible to build ethical military drones and robots, capable of using deadly force while programmed to adhere to international humanitarian law and the rules of engagement. He said software can be created that would lead machines to return fire with proportionality, minimize collateral damage, recognize surrender, and, in the case of uncertainty, maneuver to reassess or wait for a human assessment.
In other words, rules as understood by humans can be converted into algorithms followed by machines for all kinds of actions on the battlefield.
“How a war-fighting unit may think — we are trying to make our systems behave like that,” said Lora G. Weiss, chief scientist at the Georgia Tech Research Institute.
Others, however, remain skeptical that humans can be taken out of the loop.
“Autonomy is really the Achilles’ heel of robotics,” said Johann Borenstein, head of the Mobile Robotics Lab at the University of Michigan. “There is a lot of work being done, and still we haven’t gotten to a point where the smallest amount of autonomy is being used in the military field. All robots in the military are remote-controlled. How does that sit with the fact that autonomy has been worked on at universities and companies for well over 20 years?”
Borenstein said human skills will remain critical in battle far into the future.
“The foremost of all skills is common sense,” he said. “Robots don’t have common sense and won’t have common sense in the next 50 years, or however long one might want to guess.”