In the space of three years, the [Obama] administration has built an extensive apparatus for using drones to carry out targeted killings of suspected terrorists and stealth surveillance of other adversaries. The apparatus involves dozens of secret facilities, including two operational hubs on the East Coast, virtual Air Force cockpits in the Southwest and clandestine bases in at least six countries on two continents. No president has ever relied so extensively on the secret killing of individuals to advance the nation's security goals. Lethal operations are increasingly assembled a la carte, piecing together personnel and equipment in ways that allow the White House to toggle between separate legal authorities that govern the use of lethal force. In Yemen, for instance, the CIA and the military's Joint Special Operations Command pursue the same adversary with nearly identical aircraft. But they alternate taking the lead on strikes to exploit their separate authorities, and they maintain separate kill lists that overlap but don't match. CIA and military strikes this fall killed three U.S. citizens, two of whom were suspected al-Qaeda operatives. Although human rights advocates and others are increasingly critical of the drone program, the level of public debate remains muted. [One] reason for the lack of extensive debate is secrecy. The White House has refused to divulge details about the structure of the drone program or, with rare exceptions, who has been killed.