Misunderstanding the “just cause” condition of just war doctrine

In a recent article at First Things, I argued that the just war tradition holds that for a war to be justifiable, it must be morally certain that it meets just war conditions (not merely arguable or even probable that it meets them).  Some readers have objected that some of the sources I cited require moral certainty only with respect to the “just cause” condition, not the other conditions.  If so, then it might seem that we can (contrary to what I claimed in the article) be morally certain that the Iran war meets the “just cause” condition.  For war aims like liberating the Iranian people or preventing an oppressive government from acquiring nuclear weapons are (so the argument goes) surely manifestly just.

But this sort of argument badly misunderstands the “just cause” condition, and the misunderstanding is a frustratingly common one.  The implicit assumption is that the just cause condition requires merely that a war be fought for some aim that is morally good in the abstract.  But that is not the case.  As I have emphasized in previous writing on this subject, what the tradition requires is that the aim be a morally good one all things considered, and given the actual concrete circumstances under which the war would be fought.

This should be clear when we realize that almost any war would meet the “just cause” condition if we conceive of its aims in an abstract enough way.  For example, during World War II, the Japanese empire could claim that its aim was to achieve the “co-prosperity” of the countries of East Asia, and the Germans could claim that their aim was to acquire Lebensraum or “living space” for their people.  And who could object to co-prosperity or living space?  But obviously, it would be absurd to pretend that either country had actually met the just cause condition of just war doctrine.  For when we get into the details of exactly how co-prosperity and living space were to be realized (namely, via conquest) we see that the causes were not morally good.

The reality is that many of the conditions that too many people commenting on the Iran war assume are distinct from the “just cause” condition are in fact treated by the just war tradition as part of that condition.  For example, consider the eminent twentieth-century Catholic natural law theorist Heinrich Rommen (pictured above).  In his 1945 book The State in Catholic Thought he addresses just war doctrine, and devotes a section to the just cause condition (at pp. 660-65).  Naturally, he addresses the issue of whether the aims being pursued are morally legitimate.  But he also says that for a cause to be just, going to war must be a “last resort” to realizing those aims; that the proposed war really is in fact “capable of attaining its purpose”; and that “the damages caused by intervention are not greater than the damage to the common good, national and international” caused by the disorder the war aims to remedy (p. 662).  He also adds that “right intention is a necessary part of the just cause” (p. 665). 

In short, whereas some commenters suppose that having a right intention, being a last resort, having serious prospects of success, and not causing greater evils than those being remedied are additional conditions of just war doctrine, over and above the just cause condition, Rommen treats them as components of the just cause condition.  Hence, when he says that “the justice of the cause must be certain” and not have “only a probability” in its favor in order for a war to be legitimate (pp. 664-65), he means that it needs to be morally certain that all of these criteria are met.

By no means is this position unique to Rommen.  One finds it in standard Catholic manuals of ethics and moral theology in the pre-Vatican II period.  For example, the discussion of the just cause criterion in Austin Fagothey’s Right and Reason (at pp. 563-65) includes “sufficient proportion between the good to be accomplished and the accompanying evil,” “last resort,” and “fair hope of success,” as parts of the just cause condition.  Hence when Fagothey goes on to say that the cause must not only be just but must be “known to be just” and that we “must be sure of a just cause before fighting” (pp. 564-65), he means that we must be sure that all of these criteria are met. 

We find something similar in the treatment of the just cause condition in volume I of Fr. John McHugh and Fr. Charles Callan’s Moral Theology: A Complete Course (at pp. 560-66).  They argue that for a cause to be just, war must be a “last resort”; the disorder war is intended to remedy must be “so grave that it outweighs the risks and losses of war”; that when determining these potential risks and losses, a nation must factor in “the losses oneself will suffer, but also the losses that will be suffered by others” as well as harm to “the world in general or posterity”; and that in light of such considerations, “it could happen that a nation with justice on its side… would nevertheless not be justified in waging war.”  Hence when McHugh and Callan go on to say that “the government may not declare war, unless it is morally certain that right is on its side” and that “one should refrain from hostilities as long as one’s moral right is uncertain,” they mean that it must be morally certain that a proposed war meets all of these criteria. 

Now, in an earlier article at my blog and a follow-up article at Public Discourse, I have argued that the war with Iran clearly does not meet all of the criteria cited above.  Accordingly, it does not meet the just cause condition of just war (let alone other conditions such as the “lawful authority” condition, which I have argued it also does not meet).  As I noted in the First Things article, even some Catholic defenders of the war admit that the war only arguably meets the criteria cited above, rather than meeting them with moral certainty.  But as I argue in that article, the absence of moral certainty is enough to show that the war is unjust, at least if we are looking at it through the lens of the Catholic just war tradition.