Last week, I argued that many common objections to U.S. drone strikes don't hold up well under scrutiny. For the most part, complaints that "drones kill civilians" or "drones kill from a distance" are red herrings -- every weapons system can cause civilian casualties, and planes, Tomahawk missiles, and snipers all enable killing from a distance. We should worry about armed drone technologies for a different set of reasons: By lowering or disguising the costs of lethal force, their availability can blind us to the potentially dangerous longer-term consequences of our strategic choices.
Armed drones lower the perceived costs of using lethal force in at least three ways.
First, drones reduce the dollar cost of using lethal force inside foreign countries. Most drones are a bargain compared with the available alternatives. Manned aircraft, for instance, are quite expensive: Lockheed Martin's F-22 fighter jets cost about $150 million each; F-35s are $90 million; and F-16s are $55 million. But the 2011 price of a Reaper drone was $28.4 million, while Predator drones cost only about $5 million to make. (And Hellfire missiles are a steal at less than $60,000 each; you could buy one with a home equity loan.)
Second, relying on drone attacks reduces the domestic political costs of using lethal force. Sending special operations forces after a suspected terrorist places the lives of U.S. personnel at risk, and full-scale invasions and occupations endanger even more American lives. In contrast, using armed drones eliminates all short-term risks to the lives of U.S. personnel involved in the operations. (And because drone attacks don't involve "sustained fighting … active exchanges of fire … [or] U.S. ground troops," any need for congressional notification and approval under the War Powers Resolution can conveniently be avoided.)
Third, by reducing accidental civilian casualties, precision drone technologies reduce the perceived moral and reputational costs of using lethal force. Contrary to popular belief, most U.S. officials care greatly about avoiding civilian casualties. (Yes, Virginia, there is such a thing as a conscience, even in CIA officials.) Even those willing to discount the moral cost of civilian deaths understand the reputational costs: Dead civilians upset local populations and host-country governments, alienate the international community, and sometimes even disturb the sleep of American voters.
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 based in Yemen or Somalia will endanger expensive manned aircraft, the lives of U.S. troops, and/or the lives of many innocent civilians, U.S. officials will reserve such killings for situations of extreme urgency and gravity (stopping another 9/11, finally getting Osama bin Laden). But if all that appears to be at risk is an easily replaceable drone, officials will be tempted to use lethal force more and more casually.
And this, of course, is exactly what has been happening over the last four years. Increasingly, drones strikes have targeted militants who are lower and lower down the terrorist food chain, rather than terrorist masterminds. Strikes increasingly target individuals who pose speculative, distant future threats rather than only those posing urgent or catastrophic threats. And drone strikes have spread ever further from "hot" battlefields, migrating from Pakistan to Yemen to Somalia (and perhaps to Mali and the Philippines as well). Although drone strikes are believed to have killed more than 3,000 people since 2004, only a tiny fraction of the dead appear to have been so-called "high-value targets."