My purpose here is to illumine the issues germane to "just war" theory -- not to advocate its adoption. The criteria traditionally advanced by the just war theory divide into two groups: the first delineating the conditions under which it is legitimate to make war; the second specifying the kinds of actions that may legitimately be employed.
Heading the first group is the criterion of "last resort": all other means of reconciling a conflict must be exhausted before armed conflict can be morally legitimized. Generally speaking, most Americans are genuinely prepared to accept this criterion as standard practice.
Second, in order to be just, a war must be explicitly declared by a competent authority. The requirement means that a nation state has to announce that it has exhausted other means of seeking redress and is targeting a specific opponent. This keeps the process -- or would if it were taken as binding -- from treachery and deceit. It requires war -- in a certain profound sense -- to be honorable.
Third, a war can be morally just only if it has "a reasonable chance of success." That sounds crudely opportunistic, as though a war can be justified only if it can be won. But there is a profound truth at stake.
Certainly it is irrational to engage in war if it cannot possibly attain the objectives for which it is professed to be fought. If one went to war only to prove some macho self-image, or to be a hero, or to embrace martyrdom, the ethical stance would be quite different from that in just-war teaching. War undertaken for such reasons would be an instrument of self- will, or group will, but not a means of achieving meaningful social consequences.
This criterion has been given a good deal of attention in the atomic age. How can push-button atomic war possibly have a reasonable chance of success? If deterrence doesn't work, are we then to blow up an enemy as a kind of punitive retaliation for starting something? Punitive retaliation by itself would be an insufficient ground for a just war.
Fourth, in order for war to be just it must be undertaken with the right intensions; it must seek to correct some wrong or achieve some protection for righteousness and order. This criterion allows some taking of risks for the sake of results, elevating the calculative prudentiality of reasonable success to a good faith effort that can be made in the face of odds. What it rules out is war to express vindictive anger, to purge feelings of hostility, or to parade prowess.
A hypothetical response to the [recent] hostage situation in iran shows how these criteria would restrain certain kinds of action. Suppose in the first flush of dismay and anger over the taking of the hostages we had begun saturation bombing of Tehran. Such an action would have failed the tests of just war: it would not have been a last resort; it would not have been done as a result of an explicit declaration of intent; it would not have succeeded in solving the hostage problem, because the hostages would have been destroyed in the process. It would have been more a venting of national fury.
Just-war teaching applies other criteria to a conflict after it begins.
he first of these is something called the principle of proportionality. Actions taken in war must be commensurate with their consequences. You don't keep your neighbor from borrowing your wheelbarrow by shooting off his arms. Just as one is not justified in going to war unless there is some chance of accomplishing social and political objectives, so one is not justified, once war has begun, in using strategies that are utterly disproportionate in destructive consequences to one's strategic aims.
This principle is quite understandable when applied to wartime strategies. it is more complex when applied to means of deterrence which, if used, would be as disastrous to the user as to the enemy. It may be we are using for deterrence threats to employ weapons that cannot possibly pass the test of proportionality. In doing so, we may be saying we have no intention of taking just-war criteria seriously, or we may simply be hoping the bluff will work.
The final criterion of just war is the recognition of the immunity of noncombatants. This criterion appears increasingly problematic in view of modern weaponry. How can it be applied under conditions of saturation bombing? Would it have any significance at all in an atomic conflagration?
Perhaps the just-war criteria postulate a world that does not exist. If so -- if the international arena is truly a jungle of secrecy, willful malfeasance, and brutal drives -- the criteria may be quaintly irrelevant. But then also is the expectation that anyone will r egard anyone else as worthy of respect, trust , or honor.