If the original hypothetical had some military purpose (say, we know 10 of these 510 family members are in fact top ranking al-Qaeda operatives, but we don’t know which ones), then there would be a meaningful comparison between the two hypotheticals. As it stands, there does not appear to be much of a contradiction.

That scenario will be difficult to construct. As soon as costs begin to get large they become equivalent to some number of innocent lives. Money represents resources, and as long as there are absolutely poor people, it’s possible to spend small amounts of money in ways that prevent innocent deaths. Food and various public health measures cost money, and people die every day from their lack. Spending outrageous amounts of money on a war carries an opportunity cost in these lives, because even if we did none of these alternate things with the money explicitly, if it were simply not taxed, some small percentage of it would be donated to potentially lifesaving causes. The percentage spent and efficiency do not have to be very good to make a lot of lives saved out of what we’ve spent on the Iraq war, say. The percentages say that merely letting the taxpayers keep that money would have saved a whole bunch of lives. Actively using it with life-saving in mind would save a ridiculous number of lives.

In other words, the taboo against assassination exists entirely for the benefit of potential victims, who tend to be high-ranking and influential and famous and so able to perpetuate such a taboo.

I think we have a winner. Nice reasoning, Jeff.

In any case, I would hope that the modern US public disapproves of ‘terror bombing’, that is bombing designed primarily to cause human misery rather than to destroy the enemy’s means of war. As far as I know the US hasn’t used an explicit terror bombing strategy since WWII, though US bombing strategies in Vietnam are debatable on this score.

If we kill ten thousand of their soldiers, they will kill ten thousand of ours. That is an acceptable loss for our noble cause.

If we try to assassinate their leaders, they might try to asassinate me! That is not acceptable under any circumstances.

In other words, the taboo against assassination exists entirely for the benefit of potential victims, who tend to be high-ranking and influential and famous and so able to perpetuate such a taboo.

To distinguish this from the hypothesis that it’s about the specificity of the 500 family members, note that we would be just as appalled by an operation that rounded up 500 random Afghanis and killed them as a deterrent to Al Qaeda. The only thing that removes the moral outrage in the first case is our notion that intended acts are morally incommensurable with not-directly-intended consequences- a dangerous bias indeed, since those on the receiving end tend not to see the distinction so clearly.

Killing 500 people with the surname Bin Laden would have made more sense than invading a country with no links to Al Qaeda – in fact, one of the region’s few secular governments and one that Bin Laden had outright condemned. Bush kept his job for that even though the result was to reignite the country’s warring factions and incite even more terrorism.