I don't believe that humans can be reduced to homo economicus, but as a group, government officials are remarkably sensitive to financial, political, and reputational costs. Thus, when new technologies appear to reduce the costs of using lethal force, their threshold for deciding to use lethal force correspondingly drops. If killing a suspected terrorist in Yemen or Somalia or Libya will endanger expensive manned aircraft, the lives of U.S. Troops, and/or the lives of many innocent civilians, officials will reserve such killings for situations of extreme urgency and gravity (stopping another 9/11, getting Osama bin Laden). But if all that appears to be at risk is a an easily replaceable drone, officials will be tempted to use lethal force more and more casually.

What line separates the lawful wartime targeting of an enemy combatant from the extrajudicial murder of a man suspected, but not convicted, of wrongdoing? (p8).

Brutality and injustice made us raise our hands towards the sky for years; God didn’t respond us, but drones came to our rescue.

A more fundamental questions suggests itself, however. How did the most powerful military in history come to devote its elite forces and advanced technology to the hunt for a man like Qari Munib, a midlevel Taliban figure in a remote corner of the planet, half a world away from the White House and ground zero in Manhattan, more than eleven years after the September 11 attacks?

Based on his experience, he has come to believe that the drone program amounts to little more than death by unreliable metadata. 'People get hung up that there's a targeted list of people,' he said. 'It's really like we're targeting a cell phone. We're not going after people – we're going after their phones, in the hopes that the person on the other end of that missile is the bad guy.

Terrorist', noun: 1. Someone my government tells me is a terrorist; 2. Someone my President decides to kill.