Since first being introduced in Iraq and Afghanistan, their numbers have grown from 167 in 2002 to more than 7,000 today. The US Air Force is now recruiting more UAV pilots than traditional ones.
"The demand has just absolutely skyrocketed," says the commander of the Air Force's 451st Operations Group, which runs Predator and Reaper operations in Kandahar.
As their numbers have grown, so has the sophistication with which the military uses them. The earliest drones operated more as independent assets – as aerial eyes that sent back intelligence and dropped their bombs. But today the unmanned aircraft are integrated into almost every operation on the ground, acting as advanced scouts and omniscient surveyors of battle zones. They monitor the precise movements of insurgents and kill enemy leaders. They conduct "virtual lineups," zooming in powerful cameras to help determine whether a suspected insurgent may have carried out a particular attack.
"A lot of the ground commanders won't execute a mission without us," says the Air Force's commander of the 62nd Expeditionary Reconnaissance Squadron in Afghanistan.
Robots, too, have become a far more pervasive presence on America's fields of battle. Remote-control machines that move about on wheels and tracks scour for roadside bombs in Iraq and Afghanistan. Soldiers in the mountains of eastern Afghanistan carry hand-held drones in backpacks, which they assemble and throw into the air to scope out terrain and check for enemy fighters. In the past 10 years, the Pentagon's use of robots has grown from zero to some 12,000 in war zones today.
Part of the exponential rise in the use of UAVs and robots stems from a confluence of events: improvements in technology and America's prolonged involvement in two simultaneous wars.