America’s use of unmanned aircraft to combat terrorism is controversial. Supporters point out predator drones cost less to build than traditional fighter planes. With no pilots flying them, fewer Americans lose their lives. And the ability to target individual terrorists reduces civilian casualties. Opponents argue that too many innocent people are killed. And their use in Pakistan and elsewhere has made the U.S. new enemies while doing little to stop terrorism. These arguments might be moot. The drone industry is expanding as more countries acquire or seek to develop them. Drones in U.S. counterterrorism and future warfare.