Would a war against Saddam Hussein’s Iraq be a just war?

Not in the eyes of the many religious leaders who are invoking this ancient theory to preach against a war that they believe violates the definitions of justice and morality. Not in the words of peace protesters who borrow the language of St. Augustine and St. Thomas Aquinas to oppose a use of force in a far more modern context.

It is a testament to the strength and vitality of ideas developed centuries ago that they still have the power to frame a contemporary dilemma. It doesn’t hurt that the very act of determining whether a war is just or unjust carries with it a kind of moral righteousness, implying without ever saying it that God or Jesus or Allah is siding with the good guys and frowning upon – or worse – the bad.

Trouble is, “just war” theory is open to far greater interpretation than is often heard from the protests and the pulpits. And delving into those complications makes one wonder whether for some, invoking “just war” is really an elaborate excuse for saying “no war” at all.

Last week’s developments – President Bush’s stern warnings, Saddam Hussein’s evasions, the buildup of troops and the heightened prospect of an attack – add a new urgency to this age-old argument. This is one of those rare times when philosophical theory actually feels concrete and pertinent, helping us to decide when it is permissible to go to war and how war should be conducted.

Although human beings have been debating this since, oh, the fourth and fifth centuries, there are no clearcut answers. The original precepts of “just war” theory have been embellished with caveats and conditions that seem to have weighed down the ship so heavily it can never sail.

“For some, it’s become a formula for postponing what you don’t want to do anyway,” says James Turner Johnson, professor of religion at Rutgers University.

Johnson is a traditionalist, arguing that history has assigned three criteria to a just war: it must be called by a sovereign authority who has the power and responsibility to take care of the common good; it must be for a just cause, such as punishing evil, repelling attacks or restoring justice; and it must be for the right intention – namely, for the purpose of peace.

So waging war for imperialistic reasons, or to secure a supply of oil, or by an outside force without authority, is definitely not kosher.

It’s possible to argue against a war with Iraq on any of these grounds. Possible, too, to argue for an attack using these criteria.

Those who don the robe of “just war critic” don’t stop there, however. They say that a just war can be undertaken only as a last resort, only for self-defense, that it must be proportional, guarantee a minimal involvement of civilians, and have a reasonable chance of success. In other words: attack only after being attacked, kill only those who deserve to be killed, and make darn sure from the outset that you can win.

How lovely to imagine such a war, with the swiftness, certainty and surgical precision of a high-tech operating room.

But, alas, real war is a whole lot messier and its outcome harder to guarantee than a bet on the Super Bowl. I’m not sure that the powers-that-be could have promised proportionality or limited civilian casualties or even success when U.S. troops stormed Europe in World War II, but it’s hard to think of a modern war with a more just cause or right intention.

To my mind, the compelling dilemma is whether the threat by Saddam Hussein is real and imminent enough to qualify as a just cause for a just war. Here, too, good people disagree.

Michael Walzer of the Institute for Advanced Study at Princeton is skeptical about the justice of preventive war, in which the threat is distant and the opportunity to avoid conflict through other means still available. Short of war, he says, “there are things we can do, and things we are doing, which would seem to address the threat Iraq presents.”

Others argue that modern technology, weapons of mass destruction and the potential for terrorism have changed the way we need to view a “threat.” A modern-day threat can defy political boundaries or conventional sovereignty. It can be seen in Hussein’s persistent defiance of U.N. resolutions or in his systemic abuse of human rights.

On this, in my opinion, the jury that is the public is still deliberating. This question is one of the most difficult a democratic society ever faces.

That is why traditional “just war” theory can be so helpful: It attempts to provide a moral construct and a restraint to man’s most powerful and destructive urges. It does not erase the use of force from the choices that rulers and states have before them. It does not say that all force is bad, that all war is to be avoided, or even that war is only the better of two evils.

It says that the use of force is an option available to a nation under certain conditions, a precious and dangerous option that is meant to be used carefully, and with as much humanity as possible. War is hell; it’s our responsibility to find a moral regime within it.

Jane R. Eisner is a columnist for Philadelphia Inquirer.