The Obama administration's use of drone strikes is under heightened scrutiny this week, climaxing with Thursday's confirmation hearing for John Brennan, White House counterterrorism chief and President Obama's nominee to head the CIA.
Since Obama took office in 2009, the use of drones has grown 700 percent. This week the country learned that America launches drones from a secret base in Saudi Arabia.
The country also learned that the federal government considers it legal to use drones to kill Americans overseas if an informed, high-level official believes the citizen poses an imminent threat. An unclassified Justice Department memo, leaked this week, shows that no clear evidence is needed.
Human rights and civil liberties groups have protested the process for targeting terror suspects, especially U.S. citizens.
"That justifies essentially a claim that the Executive Branch can be judge, jury, and executioner," Hina Shamsi, director of the American Civil Liberties Union's National Security Project, said.
A recent case illustrates the controversy. In 2011, an unmanned U.S. drone strike killed Anwar Al-Awlaki in Yemen. He was an American citizen but also a top al Qaeda leader linked to several terror attacks.
Many in the military believe that drone strikes will continue to grow in importance but that more thoughtful debate about their use is needed.
"If the threshold gets too low and we are too casual about it, then we will forget how much scar tissue we build up in those countries," Ret. Gen. Stanley McChrystal, former U.S. Commander in Afghanistan, said.
That scar tissue is already growing. In Pakistan alone, drone strikes have killed thousands of terrorists but also more than 300 civilians.