The plain drone and the armed drone differ greatly in their impact on human security. The plain drone is essentially neutral, its impact depends on the nature and purpose of the agent wielding it. The armed drone, being a weapon of stealth and precision that carries no immediate risk to its user, encourages militarization of conflict, violations of international law and proliferation. The US use of armed drones in its global “war on terror” has caused concerns that the drone permits a warfare of questionable legality and is sparking a race towards sophisticated models whose use require international regulation. Two decades into the “war on terror”, there has been little progress towards stronger international regulation. Self-restraint in existing user states is not in much evidence. That leaves self-interest – notably fears of proliferation and a demanding technological race – as the main incentive to regulate.