The United States is the world's only military superpower, but the conflicts in Iraq and Afghanistan have demonstrated the difficulty in using that power. The U.S. military has an unmatched capability to destroy, but it does not want to cause unintended casualties.

But there is no such thing as immaculate war. The United States faces a dilemma: if it uses its firepower, it will unavoidably inflict unwanted casualties. But if it doesn't use its firepower, it undercuts a principal advantage and arguably exposes U.S. troops to greater risk.

Ten years ago, we did not think the problem would be so great. We had incidents before, but their consequences were limited, since the conflicts were brief. The wars in Iraq and Afghanistan, on the other hand, have lasted years. The longer the war, the greater the potential for accidents, which can alienate the population we are trying to protect and motivate some of them to join our enemies.

It is impossible to get the decision exactly right, since information on the battlefield is imperfect. So on what side do we err?

Yet, while asking this question, we have to recognize that something is not quite right, for our enemies target civilians. We are assured that this makes them unpopular, but if that is the case, why do the suicide bombers keep coming? Why are al-Qaeda and associated groups able to recruit so many people who are willing to give their lives to kill innocents?

In this respect, al-Qaeda bears an eerie resemblance to the nihilists and anarchists of the nineteenth and early twentieth centuries. "Murder is the principal agent of historical progress," Karl Heinzen bluntly proclaimed in 1849. "The man who would not joyfully give up his own life for the satisfaction of putting a million barbarians into their coffins carries no republican heart within his breast."

Heinzen's thesis was, in effect, elaborated by the Italian General Giulio Douhet in his classic work, Command of the Air in 1921, which made the case for the terror bombing of cities. "A complete breakdown of the social structure cannot but take place in a country subjected to this kind of merciless pounding from the air," he argued. "The time would soon come when, to put an end to horror and suffering, the people themselves, driven by the instinct of self-preservation, would rise up and demand an end to the war."

An example of this effect can be seen in the response to a recent bombing in Lahore, Pakistan. Many residents blamed the United States for provoking the bombers and demanded their government cease its cooperation. As one demonstrator explained, "militants are attacking Pakistan to express anger against the government for supporting America."

Douhet was making the case for total war. The First World War had been huge, the largest war in history, but even so, civilians and cities had largely been spared. He said that would not be the case in the future, and he was right.

Since that time, we have tried to avoid bombing cities and killing civilians. We have not always been successful, but we have tried.

But in attempting to fight a more moral and political war, are we overlooking the methods that have succeeded in the past? Can we prevail if we try to take the cruelty out of war?

In the Boer War, Britain targeted civilians on purpose, and it won as a result. "It was, however, not the arms of the enemy which directly compelled us to surrender, but another sword which they had stretched out over us-namely, the sword of hunger and nakedness, and, what weighed most heavily of all, the awful mortality amongst our women and children in the Concentration Camps," admitted S. W. Burger, the Acting State President of the defeated South African Republic.

Can we fight such a war? No. But if that is what it takes to win a war, and our enemies can employ those tactics, then how do we win? In this situation, it is probably best to avoid war, if at all possible.

In the meantime, we have to confront the dilemmas of the wars we are in.