No military technology is perhaps more viscerally upsetting than the idea of a machine, armed with a gun, making the decision on its own to kill people. It's a theme throughout dystopian fiction and films, and it animates protests against drones, despite the fact that military drones still have humans at the controls. Autonomy for weapons--where a gun turret or future machine will be programmed to press the trigger on its own--is a definite possibility in future wars. A new report from the Center for New American Security, a Washington D.C. think tank, wants to guide us calmly into understanding this future of armed thinking machines.

In his State of the Union Address last week, President Obama mentioned drones exactly once. Out of respect for human dignity, he said, our use of drones should be “properly constrained.” When he said “constrained,” Obama was referring to military drones, not toy drones, but now, he might have a personal interest in constraining smaller ones. Early this morning, while the president was away visiting India, the Secret Service found a crashed drone on the south lawn of the White House.

Drones, the monosyllabic catch-all for remote controlled unmanned aircraft, have become a striking symbol of modernity in the past decade. First as military scouts and assassins, then as delivery gimmicks and backyard toys, the simple category of craft captured the imagination of everyone clever enough to put the words “Game of Drones” together. But the history of drones goes back more than a century. This video, created by Mashable, captures a lot of that history in just nine minutes: