This moral belief may be partly due to the well-known cognitive failure of focusing on individuals. Our emotions honestly do believe that the death of one is a tragedy and the death of a million is a statistic, so we feel more squeamish about ordering the death of one person than ordering a large troop mobilization that could kill millions.
But more cynically, such a moral code clearly benefits the aristocracy at the expense of the peasantry. If I were a selfish political leader or a general, I would do everything I could to promote a moral code that says the targeted killing of people like me is very wrong. If someone were to go to war with my country, I would want then to do so in a way that killed thousands of peasants rather than me or people like me. This moral code allowed the aristocracy to treat war like a game, wasting the lives of thousands of people in pursuit of glory. It worked out great for them, and not so good for the people stuck in the middle.
Militaristic aristocrats do not care about civilians or troops. They only care about their own life and their personal power and glory. For example, modern research suggests that the leaders of Japan honestly did not care that we were carpet-bombing their cities, killing hundreds of thousands of civilians. This was irrelevant to them; their concerns were more personal:
But Hasegawa and other historians have shown that Japan's leaders were in fact quite savvy, well aware of their difficult position, and holding out for strategic reasons. Their concern was not so much whether to end the conflict, but how to end it while holding onto territory, avoiding war crimes trials, and preserving the imperial system. The Japanese could still inflict heavy casualties on any invader, and they hoped to convince the Soviet Union, still neutral in the Asian theater, to mediate a settlement with the Americans. Stalin, they calculated, might negotiate more favorable terms in exchange for territory in Asia. It was a long shot, but it made strategic sense.
In fact, Wilson argues, history suggests that leveling population centers, by whatever method, does not force surrender. The Allied firebombing of Dresden in February of 1945 killed many people, but the Germans did not capitulate. The long-range German bombing of London did not push Churchill towards acquiescence. And it is nearly impossible to imagine that a bomb detonated on American soil, even one that immolated a large city, would prompt the nation to bow in surrender.
Thankfully, civilized nations no longer carpet-bomb civilian population centers. But we still have international conventions against assassinations, and we are still squeamish about targeted killings, with the result that we are often forced to engage in large-scale street-fighting, a meatgrinder that kills troops and puts civilians at risk but does not much affect the leaders who actually caused the problem.
If we do not want to treat war like a game, if we actually want to eliminate a threat, then we need to hit the leaders rather than the troops. Troops can be replaced easily, partly because they all have friends and families that will want to avenge them if they die. Killing a thousand ground troops will accomplish almost nothing. As long as the organization has its leadership structure in place, those thousand people can be replaced. Killing the leaders will be more effective at stopping the immediate threat, and it will be a much better deterrent to other potential leaders. And even if you care more about morality than effectiveness, it should be clear that the death of one is preferable to the death of thousands.
We are learning this. We are learning that targeted killings of leaders works:
That doesn't mean that we'll see an end to terror ... But we can reduce it to a statistical nuisance, rather than a cataclysmic danger. And whatever our political views, we should acknowledge President Obama's willingness to unleash our special capabilities in our current campaign to kill terrorists leaders. He's gotten this part right and deserves credit for it.
I am troubled by any kind of extrajudicial killing, but I recognize that the killing of one person can often prevent a messy engagement that kills dozens or hundreds of people. The way forward is not to ban assassinations and revert to medieval notions of warfare and deterrence. We need to face up to reality, acknowledge targeted assassination as a legitimate strategy, and incorporate it into our legal framework so that the ability is not abused. Imagine a world where large-scale military conflict is a thing of the past, and we keep the peace by, after due process of law, arresting or assassinating the individuals likely to cause wars and terrorism. I think that this would be a better world.