In the decade since Sept. 11, 2001, the United States has developed an air force of drones to fight its new enemies. Faced with terrorists willing to take any life, we built machines that hunt and kill but don't bleed.
In the next decade, our reliance on drones and the spies who support them may increase for a different reason: We're losing friends.
Since Sept. 11, the U.S. drone fleet has grown from a few dozen to 7,000. The Air Force now trains more pilots to operate drones than to fly bombers or fighter jets. Spy drones have flown extensively in Afghanistan and Iraq, where we've fought ground wars. But killer drones have been particularly useful in Pakistan, where we can't send troops.