The use of Remotely Piloted Aircraft (RPAs or “Drones”) by the United States’ as an element within its “targeted killing” counter-terrorism effort has been both applauded as a low-cost and low-risk means of disrupting terror group operations and strongly condemned as illegal, immoral, and establishing a dangerous precedent. This paper will focus on two dimensions of lethal RPA operations: 1.) legal arguments, applying the principles of necessity, distinction, and proportionality; 2.) the effectiveness of the campaign as a counter-terror strategy, weighing costs and benefits of that campaign. These two dimensions raise questions about the status of enemy forces encountered, the shape and size of the battle-space, and the costs and benefits derived from specific actions. Studying RPA use in the United States’ counter-terror mission may be then used to consider the broader ramifications of the United States and its allies conducting a long, borderless war against al-Qaeda and associated groups.