[This story is part of a week-long series on CBC radio's Ideas about the First World War, which started in the summer 100 years ago when the heir to the Austrian throne was assassinated in Sarajevo. Listen to Frank Faulk's full documentary about Just War theory on June 27 at 9:05 p.m. Eastern on CBC Radio 1's Ideas.]

You've probably never heard of Just War theory, so it might come as a surprise to learn that philosophers, political theorists and heads of state have drawn upon it for centuries, shaping how we think about war today. But there are vocal critics of the intellectual attempt to distinguish war from murder.

Consider this: without the Just War theory there would be no International Criminal Court.

Concepts like genocide or crimes against humanity would not be part of our shared vocabulary. 

There would be no agreements between nations on the treatment of civilians or prisoners during wartime. 

But given the horrors of war – horrors that have not diminished over time – one can’t help wondering if it has been successful in putting moral constraints on what is intrinsically an act of mass violence. Is it simply a moral and intellectual fraud?

“The most neutral phrase we can use to characterize war is that it’s mass killing for a political purpose," says Brian Orend, author of The Morality of War. "But from that fact, this mass killing can be morally defensible or morally objectionable. If it’s morally objectionable then we call it slaughter or murder.”

Origin of the theory

In the West, most thinking about what elevates war to a moral and just use of violence is found in Just War theory. But the man who first gave serious thought to what makes war a moral enterprise — and not an act of mass murder — is Saint Augustine, way back in the 5th century A.D. 

Netherlands International Criminal Court

The International Criminal Court (ICC) in The Hague, Netherlands, is the world's first permanent war crimes tribunal. (Bas Czerwinski/The Associated Press)

Saint Augustine wanted to reconcile the Christian duty to “love thine enemy” with the reality of living in a violent and “fallen world.” It is in his classic work, City of God, that we see the seeds of Just War theory.

“The real evils in war are love of violence, revengeful cruelty, fierce and implacable enmity, wild resistance, and the lust of power, and such like; and it is generally to punish these things, when force is required to inflict the punishment, that, in obedience to God or some lawful authority, good men undertake wars,” Saint Augustine wrote.

Through the centuries Just War theory has continued to develop, expand and dominate discourse on war. 

“It is difficult to define war as being a moral undertaking, because actually it sounds like a contradiction in terms," says Stephanie Belanger, assistant director of the Canadian Institute for Military and Veterans Health Research.

World War One Centenary Timeline

A U.S .Army 37-mm gun crew in battle during the World War One Meuse-Argonne Allied offensive in France on Sept. 26, 1918. "I think the deepest sacrifice of those that we ask to go to war is not the possibility that they may die or their colleagues may die, but the sacrifice of their normal unwillingness to kill," says Duke University professor Stanley Hauerwas. (The Associated Press)

"Anyone who’s been to war will acknowledge that it’s chaos. It’s violent. It’s ugly. So to say that war is a moral undertaking will sound in fact perverse, like a huge contradiction in terminology.”

“I think the deepest sacrifice of those that we ask to go to war is not the possibility that they may die or their colleagues may die, but the sacrifice of their normal unwillingness to kill - and in particular that when they come back we don’t want to know what it is that they’ve had to do," adds Stanley Hauerwas, professor of theology and ethics at Divinity School, Duke University, N.C., and a Christian pacifist.

"So the whole question of what constitutes war as a moral enterprise is one that I think demands much closer moral analysis than what has normally been given it."

No sweeping judgments

Just War theory is not simply about establishing a just cause to go to war. This is why it is structured in a way that avoids making sweeping judgments about the justice of an entire war. 

Broadly speaking, it divides war into three phases: the beginning, middle and end.  And it provides different rules and categories for each phase of war:

  • Jus ad bellum refers to the justice of war, or the start of war. Crucial here are issues like just cause.
  • Jus in bello refers to justice in war. There are various rules here, in particular that you can’t directly target civilians.
  • Jus post bellum is the issue of justice after the war. It includes how to write a proper peace treaty, and how to wrap things up.

Despite the efforts of followers of Just War theory to make it less savage, as the time-worn adage goes, war is hell. And not just for soldiers. In the 20th century alone more civilians have been killed in war than actual combatants. 


Victims of the atomic bomb's destruction of Hiroshima are sheltered at a tent relief centre on the banks of the Ota River on Aug. 7, 1945, one day after the blast. (Yotsugi Kawahara/Associated Press)

It is also the century where two atomic bombs were intentionally dropped on two densely populated Japanese cities: Hiroshima and Nagasaki. According to most Just War theorists, this was an act of murder on the part of the U.S., regardless of the rationales given for dropping the bombs. 

After all, it is considered a violation of Just War theory to intentionally target civilians. It would’ve been better on Just War grounds for more Japanese and more Allied troops to die on the beaches of Japan rather than commit one murder of a civilian.

As a result, some feel Just War theory is mainly used to create justification for violence.

“From a realist’s perspective, Just War Theory is all about theological or intellectual fraud," Belanger says. "It’s about a lie that justifies self-interest.”

Orend disagrees, saying it's simply a way to deal with a world where violence is sometimes inevitable.


About a month after the Aug. 6, 1945 atomic bomb blast, an allied correspondent examines the destruction of Hiroshima amid a landscape strewn with debris. (Associated Press)

“I don’t think that just war theory is an intellectual or moral fraud. I think it’s a sincere attempt to grapple with difficult situations that the world throws at us," he says. "We realize the world is imperfect and sometimes we’re confronted with these nasty regimes, these vicious situations. And sometimes it seems like the only morally responsible thing we can do is resist such people with armed force.”

Hauerwas says the problem is that Just War theory assumes that we'll act rationally.

“I think the assumptions that Just War reflection makes about human kind assumes that we are open to moral argument in a manner that makes our desires, and particularly the desire for vengeance, subsidiary to rational adjudication," Hauerwas says. "And, of course, that’s a very high view of the human - that we are capable of that kind of reflection. The empirical evidence certainly tends to favour the presumption that we are more perverse than we are capable of rational reflection.”

Michael J. Butler, professor of political science at Clark University in Massachusetts and author of Selling a Just WarFraming Legitimacy in U.S. Military Intervention, says that as with any theory, the devil is ultimately in the details.

"And in particular, the devil is in the application in this case. I think the biggest area of fraud comes in the areas in which it is repeatedly misappropriated by those responsible for initiating war in cheap and easy moralism.”

[Listen to Frank Faulk's full documentary - Just War theory: So What? - on June 27 at 9:05 p.m. Eastern on CBC Radio 1's Ideas.]