NO AMERICAN CASUALTIES, NO PROBLEM:

In the space of three years, the 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.

Other commanders in chief have presided over wars with far higher casualty counts. But no president has ever relied so extensively on the secret killing of individuals to advance the nation's security goals.

The rapid expansion of the drone program has blurred long-standing boundaries between the CIA and the military. 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.

The convergence of military and intelligence resources has created blind spots in congressional oversight. Intelligence committees are briefed on CIA operations, and JSOC reports to armed services panels. As a result, no committee has a complete, unobstructed view.

With a year to go in President Obama's first term, his administration can point to undeniable results: Osama bin Laden is dead, the core al-Qaeda network is near defeat, and members of its regional affiliates scan the sky for metallic glints.

Those results, delivered with unprecedented precision from aircraft that put no American pilots at risk, may help explain why the drone campaign has never attracted as much scrutiny as the detention or interrogation programs of the George W. Bush era. Although human rights advocates and others are increasingly critical of the drone program, the level of public debate remains muted.

Senior Democrats barely blink at the idea that a president from their party has assembled such a highly efficient machine for the targeted killing of suspected terrorists. It is a measure of the extent to which the drone campaign has become an awkward open secret in Washington that even those inclined to express misgivings can only allude to a program that, officially, they are not allowed to discuss.

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