Targeted killing of terrorist leaders was controversial when President Bush adopted the practice in the aftermath of September 11. Barack Obama has widely expanded the practice, using unmanned drones. Rather than through acts of Congress, much less the courts, it's been driven by drone technology, and the President alone decides who lives or who dies. The CIA carries out his decisions, and it wants more drones. Mitt Romney endorsed targeted killing in Monday's debate on foreign policy. Is the intelligence agency becoming an unmanned air force? The kill-list has grown way beyond al Qaeda leaders who were the original targets. Will drone technology encourage engagement in permanent war?