In my last column, I described some of the more controversial and troubling aspects of American drone warfare in Pakistan, Afghanistan and elsewhere. Especially disturbing were credible reports that significant numbers of noncombatants have been killed in American drone strikes, including those targeted at areas previously attacked or at funerals for those killed in the initial bombing.

Since I wrote that piece, drone warfare has received significant media attention, substantially due to a nearly 6,000-word front page story that appeared two weeks ago in The New York Times. That article detailed several key features of the drone program that had not been widely reported. For example, the president’s intelligence team has prepared for him a “kill list,” people deemed to be lethal enemies of the United States. President Obama, according to the Times, has arrogated to himself final and sole authority to determine who on that list will die. The Times notes that in at least one case, the president authorized a kill order even when he knew that the intended target was surrounded by family members or other noncombatants, resulting in the deaths of women and children along with the intended target.

Despite the Times‘ painstaking efforts to portray the care with which such decisions are made, the process is fraught with uncertainty. This fact was underscored by Newsweek magazine’s Daniel Klaidman, who has reported that one of Obama’s key lawyers, Harold Koh, has at times been given only a half-hour to review the legality of a kill authorized by the president.

Among the more sensational facts to emerge from the Times piece is the White House’s method for counting civilian casualties. As I noted previously, the president’s team claims that civilian casualties from the drone program have been vanishingly small, vindicating their claims about the precision of drone warfare. According to the Times, however, the White House “in effect counts all military-age males in a strike zone as combatants … unless there is explicit intelligence posthumously proving them innocent.” This is quite an extraordinary guilt-by-association logic that if men of combat age are near a strike, they “must be up to no good.”

While the administration insists that this new weapon of choice is targeted, precise and proportionate, some officials say that our drone strikes, especially those that kill noncombatants, are creating future American enemies faster than they are eliminating current ones. Robert Grenier, who helmed the CIA’s counterterrorism center from 2004 to 2006 and was CIA station chief in Pakistan at the time of the 9/11 attacks, recently said the drone program is too broad. He cautioned that “We have been seduced by [drones]” and further warned that “We have gone a long way down the road of creating a situation where we are creating more enemies than we are removing from the battlefield. We are already there with regards to Pakistan and Afghanistan.”

“Seduced” is a good word for the new warfare. Drones are cheap. They’ve been effective at knocking off Al-Qaeda operatives. They involve no loss of life among American service personnel; they appear to enjoy broad popular support in the U.S.

So what’s the big deal? A friend of minea highly intelligent, liberal-minded guytold me recently that he supports drone warfare. Why? Because, he argued, the U.S. will continue to maintain a global military presence whether we like it or not. Given this reality, the question becomes how can we do so in the most efficient and, not incidentally, least murderous way. If our choice is massive deployments of forceas was the case in Iraq, and still in Afghanistanor drone warfare, then it’s really no choice at all. Not only are we sparing ourselves large numbers of American casualties, but we are sparing target countries large numbers of casualties as well.

Yes, he grants, drones are imperfect. They kill some people they shouldn’t. But compared to the inevitable direct and collateral damage of an invading army, drone warfare is obviously preferable.

I have thought about this argument before. And it troubles me, deeply. It assumes that we are traveling an arc of warfare in which we retire, for all time, the clumsy 20th-century warfare of tanks, boots on the ground, indiscriminate bombing and mass death. But our recent withdrawal from Iraq and plan to do the same in Afghanistan doesn’t ensure that we’ve put that particular tool of war away forever.

Another mass casualty attack on American soil or other unforeseen circumstances might yet prompt a new mass mobilization. There’s no guarantee that drones are a replacement for industrial-scale warfare. They might just be an addition to the toolbox of death. Meanwhile, we’ve endorsed a new expansion of presidential power, green-lighting unilateral and unaccountable authority over who should live and who should die, including in places in which we have not formally declared war, in circumstances in which we often don’t know who we’re killing.

Many liberals have accepted this reality and Obama’s role in it because they trust the man. His apparent judiciousness, legendary even-temperedness and background as a constitutional lawyer are all said to endow him with unique restraint in exercising such awesome power. But whether you believe that Obama is wise enough to keep us safe at an acceptable moral price is not really germane to the larger issue raised by drone warfare. These powers don’t expire when Obama leaves office.

There is also a matter of principle. American leaders have long insisted we serve as an example to the rest of the world for living according to the rule of law. On this account, the U.S. embodies a set of constitutional principles that restrict the arbitrary power of government and enlarge justice and freedom. This freedom is why, we were repeatedly told, “they hate us,” and why our principles are worth fighting for. Marginal statistical increases in our security do not, on this account, justify abrogating fundamental principles.

America has a long history of dealing death and destruction to near and distant lands, including by overthrow of popular and representative regimes and support for murderous dictatorships that suited our interests. This history, some argue, puts the lie to any pretense that we embody noble ideals of democracy and justice worth emulating. Despite that history, I have little doubt most Americans still believe the American idea is an important one. Though national security and protection of the “homeland” have been paramount priorities since 9/11, most Americans believe that even when we fight to defend ourselves, we fight the good fight and represent values that distinguish us from our fanatical and immoral enemies.

Drones may be expedient. They may result in fewer deaths than other forms of combat. But how we continue to exercise our unrivaled military power is raising disturbing questions about what principles we’ll avow the next time American citizens are attacked because they were considered legitimate targets of a foreign force convinced that we are a lethal threat to its security and well-being.

This article appeared in print with the headline “Who lives, who dies?”