A U.S. Predator drone flies through the night sky over Kandahar Air Field in Afghanistan. Such drones have been targeting groups such as the Haqqani network that are accused of attacking U.S. and Afghan forces.
Pakistani Air Force personnel guard an air base northwest of Islamabad earlier today. It was attacked Thursday by militants armed with guns, rocket launchers and suicide vests.
Aamir Qureshi /AFP/Getty Images
President Obama and John Brennan, his top counterterrorism adviser, in the Oval Office on Jan. 4, 2010. Brennan is a key voice about who gets put on the "kill list."
Pete Souza/White House