CNN Explains: Drones
02:16 - Source: CNN

The secret U.S. drone campaign against al Qaeda and its allies has transformed the nature of modern warfare, becoming a key weapon in the U.S. arsenal against suspected terrorists. Advocates see drones as an effective tool in the fight against extremists. Opponents worry about civilian casualties and loose oversight.

Here are some key facts about the U.S. drone program:

How does the U.S. use drones against al Qaeda?

Drones are Unmanned Aerial Vehicles. They are used for surveillance and targeted killings, allowing the United States to carry out certain missions without risking the lives of military personnel.

There are numerous types. The MQ-1B Predator is used for what the military calls “medium-altitude, long endurance” missions, offering intelligence gathering as well as “munitions capability.” The MQ-9 Reaper is used primarily “in a hunter/killer role,” and secondarily for intelligence, the military says. It is designed to carry out the “kill chain (find, fix, track, target, execute, and assess) against high value, fleeting, and time sensitive targets.”