military drones don't bomb.
Although decapitation strikes may get all the headlines, the vast majority of the time, drones are used for intelligence, surveillance, and reconnaissance -- what the military calls ISR. The U.S. Navy's first high-altitude drone can relay black-and-white photos covering roughly half the Persian Gulf; the Global Hawk's advanced radars make detailed images of the Earth and attempt to sniff out chemical or biological agents for telltale signs of weapons of mass destruction. Soon, the Gorgon Stare drone will "be looking at a whole city, so there will be no way for the adversary to know what we're looking at, and we can see everything," according to Maj. Gen. James O. Poss.
drones require more boots on the ground.
Most unmanned aircraft flown by the U.S. military require not just a ground-based "pilot," but also a platoon of surveillance analysts (approximately 19 per drone), sensor operators, and a maintenance crew. Some 168 people are required to keep a Predator drone aloft -- and 180 for its larger cousin, the Reaper -- compared with roughly 100 people for an F-16 fighter jet. To keep up with the demand, the Air Force has trained more drone operators than pilots for the past two years. The upside is that, according to the Congressional Budget Office, drones "are usually less expensive than manned aircraft" ($15 million for a Global Hawk versus about $55 million for a new F-16), though costly sensors and excessive crashes can negate the difference.