The Just War Doctrine is an outline set out by Catholic theologians setting forth the conditions under which a Catholic person can support a war. If these conditions are not met then the war is unjust and all Catholics are morally bound to oppose it however they can, including refusing to fight.

According to theologians like St. Augustine and St. Thomas Aquinas:

  • War must be declared by a competent authority.
  • There must be a just cause for engaging in war; that is, a grave wrong to be corrected or right to be defended.

    Pope Pius XII added:

    • Owing to the increasing destructiveness of weaponry (especially nuclear weapons), war can not be waged morally except as an act of self-defense.
    • The use of arms must not produce evils and disorders graver than the evil to be eliminated.
    • War must be waged only as a last resort after all peaceful means have been exhausted.
    • A war can be fought legitimately only if its purpose is to achieve a just end.
    According to many Catholic pacifists, this rules out pretty much all war, especially in modern times.

Actually, the idea of 'just war' vs. 'unjust war' were first developed by the non-religious (non-christian, anyway) rhetorician Cicero in his Republic.

Cicero actually split types of war into four categories: that is just, unjust, civil and 'more than civil' (foreign). Just war is that which is fought after the enemy was warned concerning the unjust loss of land or for the sake of fending off agressors (that have unjustly provoked the state). Unjust war is that which is begun from wrath rather than lawful reason. "Unjust wars are those begun without a reason. For there is no just reason for war outside of just vengeance or self defense." In more concrete terms, Cicero asserted that "no war is to be considered just unless it was openly announced and declared, unless reparation has first been demanded." (Republic 3,35) Thus, it is obvious that Augustine and Aquinas are quite indebted to Cicero for their ideas.


A very interesting discussion regarding this idea debates whether or not the Crusades were 'just wars.' In the jubilee year 2000, Pope John Paul II formally apologized for the Crusades (along with several other mistakes of the Holy Mother Church), implying that they were not. And that, I believe, is also the general concensus of today's Catholics and certainly non-Catholics. However, this is false.

Given, the Crusades were a human rights nightmare (as well as an utter military failure), and the Church has every reason to apologize for instigating them.* However, according to St. Aquinas and St. Augustine's definitions, they were perfectly legitimate! According to the Church's official line at the time, the Crusades were meant to protect Christian lands and peoples from imminent destruction by the infidel hordes. This translates to a direct attack against God. The Crusades, then, were the holiest type of war that could have been fought: in defense of God!

Before you scoff, remember also that Augustine and Aquinas' ideas were no Geneva Convention. They spent very little consideration on how a war could be carried out, only why one could be carried out (given, Aquinas dwells on the morality of a few military starategies, such as ambush). I'm sure they would not have approved of the torture, looting, raping, murdering, and dispossession of thousands of people that occurred during the Crusades, and certainly not the sack of a Christian city that occurred in the Sixth Crusade, but these issues were not raised in conjunction with the just war doctrine, at least, not at the time.

*Keep in mind, I am a pacifist (albeit a cynical one), and I don't think there should be any just reason to fight a war. And not being especially churchy I am especially against the idea of any kind crusade or jihad.

Just wanted to add my two cents worth to the fine w/u's that precede this...

With all the talk lately about the United States and their present war in Afghanistan and their “pending” war with Iraq, I got to thinking if there ever is or was what might be referred to as a “just war”. My oldest daughter ( a philosophy major) reminded me of about either Aquinas and Augustine and what they had to say on the subject many years ago. I don’t think that either of them could have possibly conceived the advancement in weaponry nor the destruction and scope of the carnage that can be inflicted in modern times . Nonetheless I’ll try and paraphrase as best as I can and let you fine folks decide if indeed there ever was a “just war.”

The first of these conditions would be described as Just Cause: It states that force may be used only to correct a grave public evil such as aggression or massive violation of the basic rights of whole populations.

Aquinas : 'a just cause is required namely that those who are attacked deserve it for some wrong they have done.”

Augustine: “We usually describe a just war as one that avenges wrongs, that is, when a nation or state has to be punished either for refusing to make amends for outrages done by its subjects, or to restore what it has seized injuriously. Those wars are looked on as peacemaking which are waged neither from aggrandizement nor cruelty but with the object of securing peace, of repressing the evil and supporting the good"'.

The second of these conditions state that only constituted public authorities may use deadly force or wage war. In other words, there must be a legitimate authority.

Augustine: “The natural order conducive to human peace demands that the power to counsel and declare war belongs to those who hold the supreme authority".

The third of these conditions might best be called “Right Intentions”. Force may be used only in a just cause and only for that purpose. Sounds a little like the first huh? Well Aquinas goes a little further

Aquinas:'The craving to hurt people, the cruel thirst for revenge, the unappeased and unrelenting spirit, savageness of fighting on, the lust to dominate and suchlike -- all these are rightly condemned in wars'.

Next we move on to the probability of success.” Arms must not be used in a futile cause or in a case where disproportionate measures are required to achieve success

Folks, I don’t think any further quotes are necessary regarding that one.

Fifth in line is what can be described as a last resort. “Force may be used only after all peaceful alternatives have been seriously tried and exhausted.”

Again, I don’t think any other words are necessary… The next two kinda blend together. The proportions. “The overall destruction expected from the use of force must be outweighed by the good to be achieved. “

Last but not least, noncombatant immunity. Civilians may not be the object of direct attack, and military personnel must take due care to avoid and minimize indirect harm to civilians.

There you have it folks. I wish some of our bible touting trigger happy present leaders from countries of all shapes, sizes and beliefs would take heed of these words.

The just war doctrine, while initially appealing, suffers from fundamental and insurmountable flaws. Its rules are overly vague, self-contradictory, and unrealistic. Also, it has unacceptable potential consequences: it sets the bar for just military intervention so high that not only would its firm application lead to an end to humanitarian intervention and other worthy ends, but such observation would be largely seen as unjust by the people of the world. I shall examine the various rules upon which Jus ad Bellum (determining whether the conditions for a just war are satisfied) and Jus in Bello (determining whether conduct within war is just) are based and demonstrate how they are flawed, incomplete, or inadequate.

The first major criticism of just war theory is based on the vagueness of the terms. What, for example, does it mean to be a ‘just authority?’ To quote The Economist: “The UN is what it is—a place where diplomatic horse-trading is conducted and states manoeuvre to secure their national interest. The position it takes on an American attack will probably be determined by whether or not the Mugabe-fêting president of France decides to wield his veto. That, surely, cannot be a measure of morality.” Likewise, the prohibition of violence carried out by “private individuals or groups” does not take into account matters of self defense. Here, the flaw is more of omission than of vagueness. Surely, there are conditions under which it is just to employ force unilaterally: when the alternative is horrific, for example. ‘Proportionality’ as a concept is also exceptionally vague. Using just enough force to win a war is a certain recipe for major casualties on both sides. By contrast, overwhelming force can reveal the hopelessness of a fight and lead to surrenders rather than combat and a reduction of bloodshed. In this sense, the idea of Proportionality is both vague and incomplete. Essentially every rule features a phrase open to wide interpretation: “a reasonable chance of success” could mean many thing to many people, likewise “last resort.” Should we respond to genocide by slowly escalating diplomatic pressure, then sanctions, then bilateral talks while thousands or millions are dying? The swiftness with which force can bring closure to an evil is a strong support not only for its use, but for its relatively rapid use once its effectiveness is determined to be likely.

It is also clear that the rules of just war can easily contradict one another. For example, how do we balance Proportionality with a “reasonable chance of success?” Do we consider the chance of success when using minimal force? When using maximum conventional forces? Or when considering even the use of nuclear or other weapons of mass destruction? The probability of a just peace is related to the strength of the attacking power, particularly in cases where superior numbers and technology will allow the sort of relatively ‘clean’ war now expected of the United States. Also, the Proportionality rule that you cannot destroy your enemy may make any just peace impossible. The complete removal of a regime may be vital to a sturdy peace. The recent American use of ‘shock and awe’ techniques reveal the contradiction, in some cases, between minimal force and discrimination. (Though the effectiveness of this tactic remains uncertain pending more complete examination of the conflict in Iraq.) A massive show of force against military targets can actually limit civilian casualties. A doctrine that contradicts itself can provide no useful model for behaviour. Likewise, one that gives different answers based on how vague terms are defined cannot be used to give definitive evidence of the justice of injustice of a particular action.

The just war doctrine, for all of these reasons, is an unrealistic mechanism for choosing to go to war or for conducting a war. While the ideas are generally appealing, close examination and case studies reveal them to fail the test of pragmatism. It must be acknowledged that no war is waged or considered from an ideal position. By definition, any situation where was is being considered is one where standard procedures have been suspended. To try and apply such high minded yet vague guidelines under such circumstances is both unrealistic and likely to bar the use of military force even when such use is justified or even urgently called for.

The final critique of the just war doctrine is that, given the modern situation, it sets too high of a threshold. Gone are the days of the Somme and a million casualties for fifty feet of captured land. Gone also are the days of indiscriminate carpet bombing like that of Dresden. Modern militaries have the capability to wage wars that, by historical standards, are remarkably clean. As such, they should not be subject to the same level of prohibition against military force. If they are willing to accept the burden of a higher expectation of care about avoiding civilian targets, and a higher level of accountability, those things should be accompanied by a lower threshold at which military force becomes and allowable, or even a preferred, option.

I would posit that no war in history has followed the just war doctrine to the nearest approximation of the letter as can be determined. Thus, if there has been a single just war in history, the satisfaction of these criteria is not a necessary condition for it being just. Further, I would say that the requirements of the just war theory do not, alone, serve to justify war. The vital condition is that overall welfare, and the welfare of the least advantaged, be boosted by the war above the level preceding the war. Namely, the war must lead to an improvement of the lives of those non-combatant members of the state or states it is being waged against. Thus, the just war doctrine is neither a necessary nor sufficient set of criteria to evaluate the justice or injustice of a war. Likewise, the contradictions of its varied axioms and their vagueness make it impossible for use as a yardstick of just conduct within war.

Finally, one point not explicitly made reference to by the just war doctrine is the state of the attacked country afterwards. Even after the 'cleanest' war, it is unlikely that the country will remain entirely stable and secure. Considerations of this nature, in terms of how the country will be both immediately after the war and in the long term, are also vital to establishing the justice or injustice of a conflict.

Log in or register to write something here or to contact authors.