Since hope is a theological virtue, one continues to hope—despite all the dismal evidence—that the current debate on the morality of nuclear armament will generate some useful ethical insights. Certainly we need some original, sophisticated arguments, to break the deadlock of a debate that has degenerated into empty rhetoric and emotional posturing. But the outlook is indeed bleak. During the past year, while innumerable ideologues proclaimed the need for a moral approach to nuclear defense, there was a marked decline in the public understanding of the moral issues at stake. And perhaps this is not surprising. During the same period, while the debate over nuclear weapons has raged within the American Catholic Church, there has been a similar marked decline in the appearance of arguments that bear the stamp of a long, impressive, and distinctly Catholic intellectual tradition. The tradition I have in mind is, of course, based on the theory of just war.

Elsewhere I have written a great deal about the particular controversy that is afflicting American Catholics.¹ In this essay, however, I shall set aside that church dispute to concentrate more generally on the theory of just war and its relevance for contemporary defense problems. I take this broader approach for three reasons: first because the dispute arming Catholics touches on a number of theological and ecclesiological points that will not hold much interest for non-Catholics; second because the just war theory can be grasped and endorsed apart from the doctrines of Roman Catholicism; its essential principles can be accepted with equal fervor by a Protestant, a Jew, an agnostic, or even a Jesuit; and third because after 1,500 years of elaboration and refinement, the just war tradition provides an unparalleled guide through the moral dilemmas of military strategy.

Modern technology has changed the face of warfare. Political leaders of past generations could never have dreamed of holding the destructive potential that their successors now hold. But human nature has not changed, and the fundamental ethical problems confronting military strategists are still the same: the need for peace and security, the protection of innocent civilians, the delicate balance of arms increases and arms control. All of these ethical problems have been explored by the proponents of just war theory, and most of them have been discussed in detail by generations of theorists.² Perhaps some day the ideologues who have “discovered” the moral problem of nuclear weaponry will realize that their discovery came several hundred years late. At the very least, it would seem fair to expect that, before dismissing the just war theory, they should try to understand it.

St. Augustine is generally recognized as the originator of the theory of just war, but the fundamental premises on which the theory is based can be traced further back, to the establishment of Christianity itself. The message of the Gospels contained two stunning breaks with the ancient understanding of war and peace, life and death. First, Jesus proclaimed Himself a peacemaker and insisted that His disciples should be the same. Of course, the peace of Christ is not the peace accepted by this world, as the Gospels very clearly point out.³ Nevertheless, the Sermon on the Mount left no doubt as to the dignity of those who work for peace here on earth.⁴ Second, Jesus emphasized with equal vigor that His kingdom was not of this world, and that consequently the values of this world must be subordinated to those of the heavenly kingdom. Again the Sermon on the Mount made the point clear, and thousands of Christian martyrs took the message literally.⁵ All human desires, even the desire for life itself, must be downgraded in the light of Christ’s eternal kingdom.

To say that Christianity is a religion of pacifism, then, is to distort the faith—almost to render it trivial.⁶ A Christian nation confronts a paradox: every human life is immeasurably valuable, and yet some other things are more valuable still. Death is preferable to apostasy, or to sin. It is better to die than to be robbed of human dignity. By the same token, there are circumstances when the use of violent force may be justifiable (as in self-defense) or even obligatory (as in the defense of one’s children). When those circumstances arise, the ordinary Christian preference for nonviolence may evaporate.

A recurrent argument in the contemporary debate claims that the early Christians refused to take up arms in the defense of Rome, thereby revealing themselves as pacifists.⁷ For the most part, it is indeed true enough that Christians refused military service. But it is also true that the Roman army during that era expended a portion of its energy in the task of throwing Christians to the lions. The fact that Christians refused to serve does not prove that they rejected military service on principle; it merely proves (in case anyone doubted it) that they considered the regime unworthy of their full support.

After the conversion of Constantine, and with the gradual emergence of the Holy Roman Empire, the situation changed radically. St. Augustine, in The City of God, emphasized the discrepancies between life in the sinful City of Man and in the eternal Kingdom. Nevertheless, he pointed out that earthly kingdoms do enjoy certain authorities in their own proper sphere, and that it might be necessary to invoke civil authority and civil force to repair injustices. The power of the state is certainly not the power of God, but if the state can improve man’s lot here on earth, then that too is a part of God’s work.

From that basic understanding, just war theory arose, to be developed by each succeeding generation of Christian thinkers. Although a history of the development of just war theory would be beyond the scope of this essay, two points bear mentioning. First, so far from being pacifist, within a few centuries after Augustine the church was advocating holy wars: the Crusades.⁸ Second, as the march of technology brought increasing deadly power into the hands of warring nations, Christians repeatedly raised the question of whether or not warfare had become too horrible to be guided by the precepts of just war theory. With the invention of the crossbow, the cannon, the rifle, and the airplane, a controversy arose that is remarkably similar to the controversy raging today. Time and again, some scholars claimed that just war theory was obsolete. Time and again, others recognized that the theory was more important and more relevant than ever.

To say that just war theory was useful, of course, is not the same as to say that it was always observed. Over the centuries, the church has been no more successful in enforcing observance of its prescriptions in the realm of military theory than it has been in its quest to rid the world of greed or of lust. Wars have always been—and have never ceased to be—occasions for the grossest sort of inhumanities. Nevertheless, one can still draw some lines and make some moral discriminations. Surely the age of chivalry, in which (in the ideal “Knights of the Round Table” formula) knights fought each other according to a strict code of warfare, was morally more advanced than our own century, with its glorification of the Blitzkrieg. Nor is it a coincidence, presumably, that the age of chivalry came at a time when the precepts of just war theory, however much they might have been abused, were at least taken quite seriously.

Over the years, and despite the multiple restatements of just war theory, the skeletal framework of the theory has remained constant. A just war must conform to two sets of conditions: those that define the circumstances under which a war may be waged (ius ad bellum) and those that define the permissible standards for the conduct of war (ius in bello). Each of these categories is itself subdivided into individual moral tests.

Ius ad bellum describes the conditions under which a nation may override the usual precept against the taking of human life. Essentially, ius ad bellum demands the fulfillment of five requirements:

First, just cause. The war must remedy or prevent a real injustice. In the past, just war theory also allowed punitive wars, to extract vindictive justice for past transgressions. Recent developments of just war theory have discarded this interpretation.⁹

Second, right intention. A war must be waged for some ostensible moral purpose. That is, self-defense is justifiable, but the imperial acquisition of territory is not.

Third, exhaustion of peaceful means. War cannot be morally justified if any other recourse is still available.

Fourth, reasonable prospect of success. An individual might choose to fight to the death against impossible odds; a ruler cannot require his subjects to make the same sacrifice.

Fifth, competent authority. The war must be declared and waged by a sovereign public authority, not by an individual citizen.

Today’s debate over the morality of nuclear warfare does not center on the ius ad bellum category, but concentrates on the ius in bello. That focus is ironic, since modern warfare raises several very knotty problems for anyone interested in ius ad bellum. For instance, in an all-out nuclear war, can anyone advance a reasonable prospect of success, by any plausible definition of that term? In guerrilla warfare, what is a sovereign authority? In an era of lightning-quick offensive weapons, what constitutes a valid declaration of war?

And the present preoccupation with ius in bello is doubly ironic, since a just cause is the first and indispensable requirement for moral warfare. If a nation goes to war for an unjust cause, nothing can salvage that war from moral condemnation, no matter how scrupulously the fighting is conducted. If the cause is just, then one turns to consider the morality of the warfare itself. If the cause is unjust, no further discussion is required.

Today, as we formulate our national defenses in response to the growing Soviet threat, we must contemplate the primary question of ius ad bellum. Could we, under any conceivable circumstances, have a just cause for warfare against the Soviet Union? To put the question in a slightly different form, is human freedom a worthy moral value, when placed on the scales opposite a ruthless totalitarian ideology? That question is rarely addressed today, perhaps because the answer seems obvious to most Americans. Yet it is important to articulate that answer, since without an answer we cannot begin to plan our strategy. Yes, under certain circumstances we could—and should—justly engage in warfare against the Soviet Union. Given the character of the regimes involved, and the relentless denial of human rights under Soviet domination, it is reasonable to envision a cause that would justify warfare even at the cost of severe human suffering.

(Perhaps some Christian pacifists would argue that the United States today is as corrupt—as unworthy of support—as was ancient Rome to the early Christians. That argument would at least be internally consistent. But could it be taken seriously?)

We turn, then, to ius in bello: the moral guidelines for ethical warfare. These can be summarized in two categories. First, proportionality: the damage inflicted must be proportionate to the goal sought. Thus, one could not justly obliterate a city if the military goal were to stop a single sniper. Second, discrimination: the warring party must make every effort to avoid damage to civilians and nonmilitary targets. A just war does not make noncombatants into targets. So terrorism is by its very nature morally indefensible.

In just war theory, the argument in favor of warfare must overcome a strong presumption in favor of peace. In the case of nuclear warfare, that argument must be overwhelming: the presumption against a nuclear strike is especially strong. On the grounds of both proportionality and discrimination, it is very difficult to justify the use of nuclear devices. The awesome destructive powers of these weapons are disproportionate to any normal political or military goal. And all nuclear weapons (at least all of the ones currently stockpiled by the major powers) would inflict massive civilian casualties. Consequently, some analysts claim that ius in bello prohibits any use of nuclear weapons, whatever the circumstances. And no respectable theorist denies that a premeditated first-strike attack would be inexcusable.

Yet these conclusions do not address the real question of nuclear defense. No strategist in his right mind contemplates the offensive use of nuclear weapons. Quite the contrary, the primary purpose of a nuclear weapon is to remain unused. This is the paradox of nuclear strategy: the paradox of intention in nuclear deterrence. The United States owns a huge strategic force of nuclear warheads, ready for use. Our national defense planners proclaim their readiness to use those warheads if necessary in defense of freedom. The Pentagon devises scenarios for fighting a nuclear war. And yet we do not intend to use our weapons. Or, to be more precise, the real use of those weapons lies in their non-use. If our missiles—poised quietly in their silos until they become obsolete—deter the Soviet Union from its aggressive plans, then they have fulfilled their purpose. We say that we intend to use our weapons if we must. But our real intention is to leave those weapons unused.

So do we or do we not intend to use our nuclear weapons? For the just war theorist, that question is absolutely crucial.¹⁰ If we intend to use them in battle, then we are contemplating a type of warfare that would violate the principles of proportion and discrimination. But if we intend to use them solely as a deterrent, then our purposes are defensive and our moral stature is undiminished.

The paradox of deterrence does not yield simple solutions. It is not enough, for instance, to use nuclear weapons purely as a bluff. If we have no intention of using our strategic power under any circumstances, and our adversary realizes this, our deterrent immediately collapses. For that matter, if our adversary has any question about our willingness to respond in extremis, he will be sorely tempted to test our will—thereby bringing us repeatedly to the brink of a nuclear holocaust. Only a firm, credible determination to use nuclear force can provide a meaningful deterrent. To bluff is not enough. We must be prepared for the worst. We must intend to do the very thing that we so dearly hope we will never do.

In the last analysis, then, we must face the horrible question of how we would respond to the ultimate provocation. If the Soviet Union launched an all-out attack on the United States, would we respond in kind? To say yes is to plan the annihilation of millions of innocent Russian civilians. To say no is to surrender before the fighting begins. There is no satisfactory solution. Our nuclear deterrent is based on an irrational premise, and proceeds from that premise to an equally irrational conclusion. So in the extreme position—faced by a Soviet willingness to launch nuclear warfare—we would be faced with two choices, each totally unacceptable.

No one is satisfied with this strategic posture. While there are widely differing opinions on how to resolve our dilemma, there is at least a universal agreement that the United States must amend its military policies. Some counsel disarmament; others, a better war-fighting capacity. Which of these options is more congruent with just war theory?

Before answering that question, one must understand the genesis of our present strategic policy. In the aftermath of World War II, the U.S. deterrent was unquestioned; we alone had the atomic bomb. But when the Soviet Union developed its own thermonuclear weapons, to complement its overwhelming superiority in conventional armed forces on the European continent, American planners were forced to devise a new policy for deterring Soviet aggression. To match the Soviet conventional threat would have been prohibitively expensive, and for political reasons (the difficulty of persuading the American people to spend that sum on defense, and forego government spending on other domestic programs), our government adopted a new strategic policy, which came to be known as the doctrine of Mutually Assured Destruction (MAD). According to the terms of MAD, any Soviet aggression against ourselves or our allies would be met with immediate, massive, nuclear retaliation.

As MAD developed, strategic planners saw stability in the very insanity of the posture. If both the U.S. and the USSR faced annihilation—so the argument ran—then both sides would be forced to behave responsibly and to avoid any possible conflicts that might prompt the dread confrontation. By that reasoning, planners concluded that a greater threat made for a stronger deterrent—the more horrible the weapons, the better. At its height of popularity, MAD proscribed any defensive measures to protect civilians against nuclear attack. The two superpowers (in theory, again) were to confront each other naked, totally vulnerable to attack, and therefore totally unwilling to risk situations that would make attack more likely.

So the theory ran. But the theory was wrong. Gradually, American planners realized that the Soviet Union did not share our belief that nuclear war was unthinkable;¹¹ the Kremlin had embarked on an ambitious campaign of diverse weaponry and civil defense, obviously contemplating strategic nuclear superiority. Nor did the Soviet Union avoid confrontations. Instead—secure in the knowledge that Americans would not resort to nuclear overkill—they pushed forward with their policies of subversion, intimidation, and outright invasion. In Hungary, Poland, Czechoslovakia, Afghanistan, Iraq, Laos—again and again the Soviets tested the Western will. In each case, it was palpably irrational for the U.S. to respond with a strategic nuclear strike, and fruitless to contemplate a conventional response against overwhelming odds, MAD failed.

Perhaps not coincidentally, MAD was also a failure from the perspective of moral judgment. Instead of a rational, proportionate defense, MAD held out one single, blood-chilling possibility: if provoked, we would touch off a conflagration that would destroy civilization as we know it. MAD failed the test of proportion, and—even more miserably—that of discrimination. As if that were not enough, it was also difficult to conceive of a victory in all-out nuclear war, and so MAD failed to satisfy the conditions of ius ad bellum as well.

Finally, the moral and strategic difficulties of MAD became impossible to ignore. First under the Carter administration and then under President Reagan, the United States has begun to move away from MAD. Instead of fixing our bombsights on Soviet cities, we have begun to aim for military installations. Instead of insisting that nuclear warfare would mean an all-out attack with the full force of our arsenal, we have begun to devise weapons and strategics that might limit nuclear conflict at a relatively low level. In effect, we are moving toward a more flexible posture, and one more in keeping with the criteria of just war theory. And we can do much more.¹²

Bishops and theologians, however, are not by nature astute military or political analysts. So today, just as the tide is turning against the MAD doctrine, moralists have suddenly discovered that MAD is immoral. Just as the Pentagon is beginning to consider just war criteria (under different names, admittedly), the clergy has announced that just war theory is outmoded. Just as the U.S. begins to establish a morally defensible strategy for nuclear deterrence, the moral seers have revealed that nuclear deterrence is immoral.

To a certain degree, the condemnation of nuclear weaponry is both understandable and even laudable. Clerics should always be peacemakers; those who represent Christianity should always exercise a countervailing influence to balance the ambitions of political opportunists. And in the tradition of just war theory, peace is always strongly preferred, and every form of warfare is naturally suspect. Still, the opponents of nuclear deterrence face a moral obligation of their own. If deterrence is unacceptable, what are the alternatives? On that score, the critics have failed miserably in their search for an ethical solution.

Consider the possible alternatives to nuclear deterrence:

1. The United States could dismantle its nuclear warheads unilaterally, leaving the Soviet Union with an effective monopoly on thermonuclear power. The historical record leaves very little doubt that the Soviet Union would use that monopoly to enforce its conquest of the world, leaving human freedoms in the dustbin of history. In effect, this choice would be the choice of martyrdom—the decision to die as a civilization rather than face the threat of warfare. For individuals, such a choice might be praiseworthy. For a government, it is not.¹³

2. We might severely reduce our nuclear arsenal, leaving a minimal deterrent against Soviet strategic attack, but making our own posture unthreatening to the Soviet Union. In other words, we could retain a nuclear deterrent useful only in case of a direct attack on our country. But this option leads to two companion dangers. First, our remaining deterrent could only be aimed at the most vulnerable targets in the Soviet empire: the cities. So we would be perpetuating the city-heisting strategy that makes MAD morally indefensible.¹⁴ Secondly, we would be sacrificing the security of our allies in NATO and around the world. Uninhibited by American deterrence, the Soviet Union could conquer the other, weaker countries at their leisure—leaving the U.S. as the last domino, awaiting the inevitable final assault. In the process of these serial conquests, the Soviet Union would certainly inflict massive casualties in many different conflicts, and after the Soviet conquest there would be more lives lost in the Gulags that would spring up around the globe. In other words, by our efforts to avoid the danger of nuclear war with its massive casualties, we would be guaranteeing the occurrence of many smaller wars, each with its own casualties.¹⁵ The toll in human suffering would probably be quite similar; the cost in human freedom would be incalculably higher.

3. We could bluff, retaining our weapons but abandoning our intention to use them even under the most extreme provocations. But this choice would run the risk of inviting Soviet adventurism. As repeated tests met with repeated passive responses from the West, the Kremlin would become increasingly aggressive and provocative. At best, the result would be an eventual piecemeal conquest of the free world. At worst, we would abandon our passive intentions and launch a nuclear war in response one such test.

4. We could negotiate an arms-control agreement, whereby both sides would make their strategic forces less threatening and more stable. Theoretically, this solution would be ideal from every perspective. But the practical difficulties are considerable. After a generation of negotiation on arms limitations, we are no closer to a lasting peace; few Americans would say that they are more comfortable now, in the wake of the SALT talks, than they were a decade ago. The arms race continues, unabated. Each side improves its military power, within whatever constraints the agreements enforce. (In fact, the Kremlin has shown few scruples about violating established agreements when they prove incompatible with Soviet plans.¹⁶) Indeed, a glance through history suggests that arms controls work only as long as the powers involved find them useful.

Even if the Soviet Union and the United States did somehow achieve a workable arms-control agreement, our problem would not be solved. How long would it be before a new set of nuclear powers threatened the same sort of worldwide destruction? Several other nations already belong to the nuclear “club”; several more are on the threshold. Having unlocked the secret of thermonuclear might, mankind cannot now make that power disappear, however attractive that dream might appear. Like it or not—and very few people like it—we are faced with the probability that nuclear weapons will exist for years if not forever.

That sobering realization should add a fresh perspective to the current argument about armaments. Is an arms race per se immoral? While we are pouring billions of dollars into the development of weapons that remain unused, the price is not too exorbitant if the result is an honorable peace. Nor are arms races in themselves likely to increase the danger of war. Most historians agree that an arms race in Europe contributed to the causes of the first World War; on the other hand, most historians also agree that the failure of the Allies to match Hitler’s weapons build-up made World War II possible.¹⁷ Arms races, like weapons themselves, are neither moral nor immoral. Morality is determined by the motives and strategies of the human beings who guide government policy.

An arms race in today’s Cold War could—if guided by the proper consideration for nuclear morality—lead us out of the ethical morass that MAD has occasioned. With our spectacular technological capacities, we can create defenses that make nuclear attacks less likely to succeed, and therefore less threatening.¹⁸ We can design missiles and other weapons—both nuclear and conventional—that possess a higher degree of accuracy, thereby guaranteeing a greater discrimination between military and civilian targets. We can increase our ability to meet conventional attacks with conventional defenses so that we do not invoke a nuclear threat against a small-scale offense. We can devise an overall military strategy that meets each potential challenge with a proportionate, convincing deterrent.

Just war theory is not outdated; it is merely out of fashion. And the results of that change in fashion are evident all around us: we are simultaneously frightened by the morality of our defensive posture and the possibility that it might not be secure enough to save our lives and our freedoms. Still it is not too late to begin thinking once again in terms of just war theory. Perhaps it is even possible to hope that, once the present confusion is abated, moral theorists will shed some new light on the need for a sane and sound strategic defense.

In one respect, a just war is just like any other war: it cannot be successfully prosecuted by someone who is not prepared for the battle. We cannot assume that the United States and its allies would conjure up a morally upright defense during the heat of battle. And if the appropriate weapons and strategic plans are not available in time, neither just nor effective defense is possible. We hope never to fight a war, but if we must fight we should fight justly. The time to begin planning a just strategy is now.

This essay was previously published in Arguing Conservatism: Four Decades of the Intercollegiate Review, pp. 512–521.

1. The Bishops and the Bomb: The Morality of Nuclear Deterence, Heritage Lecture Series no. 16 (Washington, DC: The Heritage Foundation, 1982); “Regina Pacis, Ora Pro Nobis,” Catholicism in Crisis, I, no. 2 (January 1983); “Draft’s Assumption Questionable,” syndicated column appearing in Sacramento Union, Philadelphia Inquirer, etc., November 1982. See also Justice and War in the Nuclear Age, Philip F. Lawler, ed. (Washington: Univ. Press, 1983). ↩︎
2. The single indispensable book, for anyone interested in just war theory, is The Conduct of Just and Limited War, by William V. O’Brien (New York: Praeger, 1981). All but the must serious students will find that O’Brien answers all their questions even those who want to know more will find O’Brien’s footnotes and bibliography exhaustive. Also helpful are James T. Johnson, Just-War Tradition and the Restraint of War (Princeton, NJ: Princeton Univ. Press, 1982), and Paul Ramsey, War and the Christian Conscience (Durham, NC: Duke Univ. Press. 1961). An interesting viewpoint is expressed by Michael Walzer in Just and Unjust Wars (New York: Basic Books, 1977). With particular reference to the Catholic bishops and their Pastoral Letter, see Lawler (ed.), Justice and War in the Nuclear Age. One of the bishops drafting that Pastoral has himself written a fine introduction to the topic: John J. O’Connor, In Defense of Life (Boston: St. Paul Edition, 1981). ↩︎
3. The biblical references are numerous: Luke 12:51; Rom. 3:17; I Thes. 5:3; I Peter 3:11. And this is the peace that “passes all understanding” (Phil. 4:7). Nor is this theme absent from the Old Testament, as witness Jeremiah complaining against those who cry “Peace, peace, when there is no peace” (Jer. 6:14, 8:11, 12:12). ↩︎
4. Matt. 5:9; James 3:18. ↩︎
5. Matt. 5:11; Rom. 12:14. ↩︎
6. Matt. 10:34; Luke 12:51. ↩︎
7. There is some irony in hearing Catholic clergymen cite the early Christian church as a model from which modern developments have departed. Until quite recently, that was the standard criticism made by Protestants against the Roman Church. ↩︎
8. Frequently, today’s pacifists cite St. Francis of Assisi as an exemplar of Christian pacifism. That is absurd. St. Francis preached a crusade. See Regine Pernoud, The Crusaders (New York: Putnam, 1962), 221– 23; or Omer Engelbert, St. Francis of Assisi (London: Burns Oates, 1950), 207–11 and passim. ↩︎
9. This development was made fairly explicit by Pope Pius XII. See the interpretation placed on that pope’s thoughts by Father John Courtney Murray, “The Uses of a Doctrine on the Uses of Force,” in We Hold These Truths (New York: Sheed and Ward, 1960), 255–256. ↩︎
10. This “paradox of intention” in nuclear deterrence has been explored most productively by Michael Novak. ↩︎
11. Richard Pipes, “Why the Soviet Union Thinks It Could Fight and Win a Nuclear War,” Commentary (July 1977), 21–34. See also Kenneth Adelman, “Beyond MADness,” Policy Review 17 (Summer 1981), 79–80. ↩︎
12. Angelo Codevilla. “Justice, War, and Active Defense” in Lawler (ed.), Justice and War in the Nuclear Age, 83–98. ↩︎
13. Rev. James V. Schall, S.J. “Intellectual Origins of the Peace Movement,” in Lawler, op. cit., 27–61. ↩︎
14. This argument has been forcefully made by Ambassador Edward Rowny, chief negotiator at the START talks, in discussions with the American bishops. ↩︎
15. See Edward Luttwak, “How to Think About Nuclear Weapons,” Commentary 74 (August 1982), 21–28. ↩︎
16. Jake Garn, “Soviet Violations of SALT I,” Policy Review 9 (Summer 1979), 11–32. ↩︎
17. George Weigel Jr., The Peace Bishops and the Arms Race (Chicago: World Without War Council, 1982), 21. ↩︎
18. One such hopeful possibility is spelled out in great detail in Lt. Gen. Daniel Graham’s High Frontier: A New National Strategy (Washington: High Frontier, 1982). ↩︎