As a theoretical matter, remotely piloted vehicles are simply a tool of warfare, morally indistinguishable from manned aircraft. The more efficiently the U.S. can target and kill its enemies, the better. And drones are cheaper to operate, carry far less risk for American military personnel and make it easier to collect intelligence than their manned counterparts. In reality, though, the U.S. uses drones differently than it uses traditional weapons. Because they’re small and cheap, they’re in constant operation in parts of Pakistan, Yemen and Somalia — and thus much more likely to be used to deliver lethal strikes. We’ve gone from a policy of firing only on high-value targets, such as senior terrorist leaders, to one of engaging groups of young men who present the mere “signature” of militant groups.