The major advantage to killing suspected terrorists—to put the matter bloodlessly—is that it removes important, skilled operators from the ranks of the enemy when their capture may not be an option, and it does so without significant litigation risk. Just as important, the threat of force compels those on the run to play defense. Drone strikes rely on spies, on intercepted phone calls, and on other forms of intelligence to pinpoint their targets. To reduce exposure to drones, terrorists must trust fewer people, talk on the phone or use the internet less, and otherwise minimize their contact and communications. In so doing, however, they become less effective as terrorists. An [ Anwar al-] Awlaki who cannot use a computer or phone cannot inspire others to join the jihad or instruct recruits on the best targets to strike.

Such strikes also free the United States from complete dependence on allies. . . . If the United States had sought to have [Awlaki] arrested, the Yemeni government would probably not have even bothered to try; and if it did try, it probably would have failed. In any event, Yemen lacks an extradition treaty with the United States, and its record of holding high-value detainees in its own prisons is poor. . . . For now, at least, the legal authority to use lethal force seems relatively secure, at least for those threats linked solidly to Al Qaeda, the Taliban, or groups the government can reasonably construe as “associated forces.” [Emphasis added.]