Turning to the question of civilian casualties: All armed conflicts cause civilian casualties, and most modern conflicts have done so in large numbers, in part due to the fact that insurgents often hide among the civilian population. The 2006 Israeli conflict with Hezbollah and its 2009 and 2012 battles with Hamas in Gaza, the 1999 Russian war with Chechen rebels, and the final stages of the struggle between Sri Lanka and the LTTE (Tamil Tigers) all killed more civilians than combatants, in some cases substantially more. Although the U.S. has not caused civilian casualties at rates that high, there have been memorable examples of civilian casualties in each of the recent conflicts in which we have been involved, and those casualties were caused by all kinds of weapons systems. The 1991 Gulf War involved the Al-Firdos bunker airstrike that killed up to 400 civilians. The Kosovo campaign included airstrikes that hit the Chinese Embassy in Belgrade and struck a civilian train in the Grdelica gorge. The 2003 Iraq War included civilian casualties caused by Marine ground troops in Haditha and military contractors in Nisoor Square, while a cruise missile strike in 2009 killed approximately 35 civilians at al-Majalah in Yemen.

Like any other weapons system, drones have caused civilian casualties. But they also have the potential to dramatically reduce civilian casualties in armed conflicts, and particularly in counterinsurgencies. Their ability to follow targets for days or weeks accomplishes two things that contribute to saving the lives of innocents: First, it confirms that the target is engaged in the behavior that put them on the target list, reducing the likelihood of striking someone based on faulty intelligence. Second, by establishing a "pattern of life" for the intended target, it allows operators to predict when the target will be sufficiently isolated to allow a strike that is unlikely to harm civilians.

Another, less obvious, feature that reduces civilian casualties is that drones are controlled remotely, so the decision to employ a weapon can be reviewed in real time by lawyers, intelligence analysts, and senior commanders without any concern (in most cases) that a hesitation to act may cost lives. Even more importantly, the operators themselves are not concerned for their own safety, eliminating the possibility that the combination of tension, an unexpected occurrence, and a concern for personal safety leads to weapons being fired when they shouldn't be.

This potential of drones to vastly reduce civilian casualties was not fully realized at first, but it has been dramatically attained in the past few years.

In 2007, the U.S. Army and Marine Corps began disseminating a new Counterinsurgency (COIN) Manual that emphasized the need for soldiers to be involved in nation-building and bolstering local civil-society institutions, in addition to defeating insurgents militarily. Part of implementing this strategy involved minimizing civilian casualties. When Gen. Stanley McChrystal took command of ISAF (International Security Assistance Force) in Afghanistan in 2009, he emphasized the need to continue reducing civilian casualties in all phases of operations. He assigned teams of civilians and military officers to conduct root-cause analysis of every civilian casualty in theater and tasked them with developing protocols to eliminate such deaths.