In thinking about drones strikes and targeted killings, it can be instructive to picture them hitting people you know, either deliberately or as collateral damage. Doing so may not even be much of a stretch, nor should it be. (It’s already the case for people living in parts of Pakistan and Yemen.) Last week, I moderated a live chat on the ethics of drone warfare with Michael Walzer, the author of “Just and Unjust Wars”; Jeff McMahan, a professor of philosophy at Rutgers, who has also written about just-war theory; and The New Yorker’s Jane Mayer, who is a master of the subject. The discussion took some interesting turns, touching on the idea of a secret committee that the President would be asked to check with before killing an American and the question of whether China would ever assert the right to call in a drone strike on a dissident living in San Francisco. After Walzer and McMahan suggested some criteria for strikes—criminality, risk of American lives—I asked them this:

Doesn’t a journalist working abroad who is about to release classified information about a war crime—thus committing a crime—that will provoke retribution or a break with allies—endangering Americans—fit this definition of a target?

Walzer didn’t initially think that it did. The danger to Americans, he said, had “to come directly not indirectly from the target before he can be a target.” McMahan had a different view:

If the release of classified information really would seriously endanger the lives of innocent people and the only way to prevent the release of the information was to kill the journalist, then the journalist would be liable to attack. But the evidential standards in such a case would be very high and would be unlikely to be satisfiable in practice.

“So Michael wouldn’t kill the journalist but Jeff just might…” I posted, and the chat moved on. But the question of the journalist is worth dwelling on, because it gets at some of the fundamental problems with the targeted-killing program. Who is “dangerous”? And who decides? A Justice Department white paper laying out the circumstances in which the President can kill Americans talks not only about Al Qaeda but also about “associated forces,” not clearly defined. Michael Crowley, of Time, pointed out that Jeh Johnson, the former Pentagon general counsel, has said that “Our enemy does not include anyone solely in the category of activist, journalist, or propagandist,” and I don't mean to say that the current Administration has adopted the logic that it does, though that “solely” can do a lot of work. The vagueness could easily increase with the passage of time, as targeted killings shift from a policy to a precedent. The logical chain, as illustrated in our chat, can move very quickly.

I wrote to McMahan afterward to follow up; he noted that chats are not exactly conducive to conveying qualifications. He also wrote,

First, the claim that it could in principle be permissible to kill a journalist if that were the only way to prevent him or her from releasing information that would result in the deaths of innocent people was a claim about what’s in principle possible but I think it has almost no practical relevance. Such cases are so unlikely to arise that they’re hardly worth taking seriously. Journalists are seldom in possession of information that, if published, will result in innocent people being killed. And even if a journalist were to have such information and be tempted to release it, there would almost certainly be other ways than killing of preventing the release.

McMahan offered a scenario that he thought would fit: a hypothetical village occupied by Nazis, whose inhabitants must decide whether to kill “a Quisling journalist” who is about to reveal that some of their neighbors are secretly Jewish. (A somewhat different circumstance, since a secret is being delivered to the governing power rather than suppressed by it.) “But there are almost never real cases of this sort,” McMahan added, which is why the “only reasonable rule,” in terms of law and policy, if not ethics, was that journalists were protected from attack. (Both he and Walzer distinguished between the ethical, legal, and political issues.)

That is not entirely reassuring. Whatever one thinks about the actual effect that journalists have, governments, including the Obama Administration, routinely claim that various pieces of information—from the location of a secret prison to a drone strike to any number of things in the Wikileaks files—simply can’t be published for reasons of national security. It is not an exotic scenario. (A government may also go after sources; see Jane Mayer on the Thomas Drake case.) Journalists know that there are circumstances in which information puts lives at risk—that’s one reason it’s a hard job. The question I posed was a circumstance that even the most careful journalist could imagine being in: revealing not troop movements or nuclear codes but a war crime. Journalists contend with assertions that publishing pictures of American wrongdoing leads to retribution, and even aids terrorists. (Abu Ghraib comes to mind.) In that case, the obvious answer is that, once a war crime has been committed, the only defense that we have is that we are as outraged as anyone, and that it’s best that the American press, rather some Al Qaeda Web site, show that it can be trusted to tell the truth.