They were all-seeing eyes in the sky ("a constant stare," as drone promoters liked to say) and surgically precise in their ability to deliver death to evildoers. Above all, without pilots in their cockpits, they were, in terms of the human price of war (at least when it came to the lives that mattered to us), cost free. They transformed battle into a video-game experience, leaving the "warriors" -- from pilots to generals -- staring at screens. What could possibly go wrong?

As it happened, so much went wrong. It often proved hard for the drone operators to tell what exactly they were seeing on those video feeds of theirs and mistakes were regularly made. In addition, drones turned out to kill with a remarkable lack of discrimination, while putting whole rural populations that fell under Washington's robotic gaze into a state of what, if they had been American soldiers, we would have called PTSD. Worse yet, as recent events in Yemen indicate, drones proved remarkably effective weapons not in staunching terror outfits but in spreading terror, and so became powerful recruitment tools for extremist groups.  In rural societies repeatedly attacked by the grimly named Predators and Reapers, the urge for revenge was apparent.