Deterrence and Preemption

Strategic Insights, Volume I, Issue 8 (October 2002)

by Daniel Moran

The essence of the defensive, Clausewitz tells us, is "awaiting the blow"—"the only test," he adds, "by which defense can be distinguished from attack in war." Like many of Clausewitz's important statements, this one combines the characteristics of a truism and a challenge: self-evident on the one hand, provocative in its simplicity on the other. The latter effect is heightened when this first proposition is set alongside another, more famous one: that the defensive is "the stronger form of war," a claim Clausewitz justified with the lapidary observation that, if it were not stronger, there would never be any reason to adopt it. Clausewitz's discussion of the implications of these ideas, to which the sixth book of On War is devoted, was in his own eyes unsatisfactory, "only a sketch," in need of thorough revision, which he did not live to accomplish. Even had he done so, however, it seems certain that questions would have remained as to exactly how and under what circumstances the advantages of waiting would accrue, and of when these would constitute a source of strength for which other advantages should be sacrificed. Such decisions, Clausewitz insisted, would always remain matters of judgment based partly upon instinct, and were not subject to scientific demonstration.

Clausewitz's discussion of the defensive in war was confined to the interaction of armies on a battlefield, and did not rise to the level of what we would today call "national strategy." Yet his analysis included a number of elements that resonate beyond the immediate clash of armed forces. The advantages of waiting, in Clausewitz's account, are partly material—the opportunity to amass resources, to choose and prepare a strong position, to exploit the effects of friction upon the attacker, and so on—but chiefly, and more consequentially, moral. The side that awaits the blow will usually possess a superior basis upon which to mobilize its own population, even to the level of engaging in insurrectionary violence and "people's war," a form of resistance that may persist long after a state's regular forces have been vanquished. It may also be more likely to attract the support of important allies, since the available pool will include states that may have no special sympathy for the defender's cause, but that may nevertheless fear the consequences of his destruction for the balance of forces internationally. At the same time, however, the defender bears the psychological burden of his passivity. In the end, Clausewitz argued, only offensive action can produce decisive results. The critical decision for the side that waits is thus when and how to seize the initiative.

The advantages of awaiting the blow must in any case be measured against the likely weight of the blow itself. Clausewitz took for granted that a state capable of contemplating an aggressive policy would also be able to survive whatever initial attack might be brought against it. The notion that a weak or exposed state might seek to improve its chances by deliberately taking the offensive seemed to him implausible. His native Prussia was one such state, and Clausewitz never wavered in his conviction that its natural strategic stance must be defensive, based upon a combination of armed forces strong enough to inspire the respect of potential opponents, plus a foreign policy designed to ensure that Prussia would never fight alone.

The future would favor other ideas. By the turn of the twentieth century all the European powers—Germany prominently among them—had become convinced that the key to strategic success lay in their ability to launch a powerful attack at the outset of a war, and that the risks of awaiting such a blow far outweighed those of delivering one. Among students of the First World War the resulting strategic posture is sometimes described as "the cult of the offensive," a phrase that prejudices the issue to the extent that it suggests that those who accepted this outlook were somehow acting more irrationally than is usual in such matters. Yet there is no particular reason to believe the men who carried Europe over the brink into war in 1914 were laboring under any greater misapprehension than their descendents do today. The fog of peace is as dense as it ever was. In addition, there is no question that the social and technological forces that led them to their false judgment—a combination of increasingly lethal weapons and increasingly efficient means of military mobilization—have continued to operate.

Belief in the potential decisiveness of an initial attack largely accounts for the persistence of overt military aggression, despite much evidence of its exorbitant costs and likely futility. Revolutionary insurgency presents an obvious exception, embracing as it does a theory of victory that discounts initial results in the hope of creating favorable social and military conditions later on. Those who seek to employ regular forces for aggressive purposes, on the other hand, routinely calculate that a sufficiently stunning opening blow, even against an inherently stronger adversary, will create new facts so compelling that pre-war estimates of relative strength will no longer apply. The continued credibility of this sort of calculation in turn complicates the lives of those who seek to deter attackers by threatening retaliation, since they can never be sure that even the most fearsome military capability will convince aggressors that the leverage gained by striking first will not be decisive in the end.

Deterrence

The logic of deterrence is thus more elusive than it may appear at first glance, especially if that glance is conditioned by the long nuclear stand-off of the Cold War. Nuclear deterrence is deterrence in radically simplified form, since the destructiveness of the weapons themselves tends to disabuse those who hold them of any notion that mere audacity or cleverness could allow them to evade the consequences of their use; though it is worth recalling that even in the nuclear arena the hypothetical dangers of a "decapitating" first strike have proved capable of stirring up intense anxiety from time to time. Nuclear deterrence—which amounts to little more than an exchange of hostages on a massive scale—is also unusual in that, at least as between the Soviet Union and its Western opponents, both sides were tacitly willing to admit to being deterred, a fact that contributed to the transparency, and hence the stability, of the nuclear balance.

In contrast, conventional deterrence is more enigmatic, at least to the extent that it is difficult to observe in action. For those who like to envision the international system as a Hobbesian realm of eternal struggle, in which the final goal must always be the maximization of power, deterrence becomes something like gravity, a universal force whose effects vary with the size of objects and their distance from each other. This line of reasoning can produce peculiar results. If every day of peace may be chalked up to successful deterrence, it follows that every aggressive act must be put down to deterrence failure, a disconcerting analysis from the point of view of the victim, who may be held to have erred in being insufficiently formidable. It is on this basis, for instance, that some scholars assign Great Britain a major share of responsibility for the outbreak of the First World War, a perfectly absurd idea, but one that may survive indefinitely on the nourishment of theory alone.

In reality, of course, deterrence is not the universal substrate of international politics. For most countries at most times it is entirely irrelevant. No one would propose, for instance, that the United States and the United Kingdom exist in a state a mutual deterrence, even though both possess nuclear weapons ideally suited to that purpose. Deterrence works most convincingly between known adversaries who share a common estimate of each other's hostile intentions. Its application to more diffuse threat environments, such as has prevailed since the Soviet Union's demise, is less precise, but still reasonable, particularly for a country like the United States, whose military posture combines enormous strength with a force structure intended, as far as possible, to minimize the leverage gained by early success. Even an aggressor unmoved by the threat of massive retaliation in the long run—because he believes his initial victories will change things so dramatically that the threat will be neutralized—may nevertheless stay his hand if he can be persuaded that the time available to make his crucial opening move will be too short. It is partly for this reason that the United States relies so heavily on forward-deployed naval forces, long-range strike air craft, and so on. Its force structure is tailored to the task of conventional deterrence not only by virtue of its strength, but by virtue of its agility, which deters aggressors by alerting them to how small the window of opportunity created by their initial attack may be.

Deterrence in this form is less robust and reliable than that created by conditions of "mutual assured destruction." However swift and formidable the forces of order may be, it seems certain that there will always be some who are prepared to try their luck. Within this sorry group, moreover, a special problem arises around threats that are deemed "undeterrable," a concept that turns upon a perhaps excessively fine logical distinction. Any aggressor at the moment of his aggression is undeterred. For him to be thought "undeterrable" requires an additional assumption: that nothing the victim might have done in advance could have held the attacker off. Such a judgment must always be somewhat speculative, particularly when the adversary is a government, even the most reprehensible of which must possess some sort of social base it wishes to preserve. If Hitler's Germany is today widely considered to have been an "undeterrable" threat, it has more to do with prevailing perceptions of Hitler's personal psychopathology than with any estimate of his political ambitions. Stalin's Soviet Union has as good a claim to be regarded as a world-historical wellspring of evil. Yet it was never regarded as "undeterrable," even by those who had born the brunt of Hitler's aggression. On the contrary: the policy of containment by which the Soviet Union was eventually defeated was decisively shaped by the earlier confrontation with National Socialism. To those who had to look the Nazi menace in the eye, the inference was not that every fledging demon must be strangled in its crib, but rather that safety required great strength and constant vigilance. They remained content to await the blow, and in the end it never came.

For the United States above all, a propensity to wait was a well-established element of foreign policy long before the Cold War turned patience into a strategy. Faced with a world on fire, the United States has generally preferred to be pushed, rather than to jump into the flames. It was agonizingly slow to enter both World Wars, despite the enormity of interests at stake, waiting in the latter case until most of Europe and much of Asia were almost literally in ashes before committing itself; and even then only in the wake of a direct Japanese attack that the American public persists to this day in regarding as a surprise. A willingness to deter threats and postpone confrontation, rather than to force the issue by simply taking the bull by the horns, may well be the most natural stance for a nation that seems perennially disposed to believe time is on its side. If that stance is now being called into question, it is because the underlying confidence on which it has been based has been eroded by recent events.

Preemptive Attack

The emergence of preemptive attack as a new element in America's strategic repertory has been motivated by the rise of terrorist organizations with no discernable political agenda that might be thwarted by a swift military response; nor any social base whose survival might be threatened; plus the realization that whatever blow may be in the offing will probably fall upon the United States itself, and not on some overseas outpost, nor a less fortunately situated ally. The sense that terrorist groups, or at least their individual members, are undeterrable, is heightened by the suicidal nature of their tactics. It seems self-evident that someone who is not merely prepared to die for a cause, but actively planning to do so, cannot be deflected by any threat of retaliation. This assumption, it must be admitted, has not been thoroughly tested. There may be forms of reprisal so horrific as to cause even a suicide bomber to think twice—though it is difficult to think of any that would also be acceptable to democratic public opinion (which would in turn deprive the threatened retaliation of its credibility). And in the specific case of suicidal adversaries who imagine themselves embarked upon some sort of sacramental mission, even a threat to blow up the world might not suffice.

In such circumstances the advantages of awaiting the blow are displaced by an urgent desire to intercept it before it can be launched. That, at any rate, is the accepted meaning of a preemptive attack: a blow delivered to forestall another that is either already on its way, or so thoroughly prepared that waiting for its arrival is manifestly self-destructive. Although a preemptive attack lacks the defining characteristic of the defensive as Clausewitz conceived it, those who employ it always do so in the expectation that moral responsibility for the results will be assigned to their opponent—an expectation that history suggests will not always be fulfilled. At present, however, the adoption of such a strategy by the United States remains at the stage of a thought experiment. It is a declaratory policy of which the world has been given due notice, but one whose exact dimensions and practical application remain to be worked out.

The progress of that experiment has been complicated by the effort to graft the idea of preemption onto America's long-standing confrontation with Iraq, a country now proclaimed to have entered the category of undeterrable threat by virtue of its (again, long-standing) efforts to acquire nuclear weapons. There is no desire here to add to the deluge of punditry that has poured forth over the question whether an invasion of Iraq is justified or advisable, or whether, if Iraq were to acquire nuclear weapons, it would be more likely to use them than other countries similarly equipped. Even someone inclined to answer "yes" to both those questions may nevertheless object to the characterization of current American strategy as preemptive. It is rather a strategy of preventive war, in which an attack is launched not to forestall an impending blow, but to take advantage of currently favorable conditions, in anticipation that those conditions may deteriorate in the future. This is a distinction of considerable analytic utility, and one that may prove useful in the development of whatever new international norms may be required to deal with emerging threats from non-state actors. Yet one feels the water is already becoming muddied. I write these comments having just finished grading the final examinations for a course on modern military history. There I find, to my surprise, that my students, who are professional officers, now routinely describe the German attack on the Soviet Union in June of 1941, and (even more alarmingly) the Japanese attack on Pearl Harbor a few months later, as "preemptive"—an illustration, if nothing else, of how easily the confusions of the present can obscure our understanding of the past.

The advantage of preemption as a policy category, as has been suggested, is that it seeks to shift moral responsibility to the other side, while seizing the military initiative for oneself. Its disadvantage is that it invites a demand for direct evidence that some sort of attack is impending. The Bush administration's failure to produce that evidence has in turn needlessly transformed the argument from one about national interest into one about semantics and spin. Similar difficulties have arisen around the effort to characterize Iraq, or at any rate Saddam Hussein personally, as "undeterrable." The idea that Iraq would employ a new nuclear arsenal to attack the United States (or Israel) is in the strictest sense unknowable. The only state to use nuclear weapons immediately after obtaining them is, of course, the United States itself, under somewhat unusual circumstances. On the basis of past performance, at any rate, Saddam does not obviously qualify as an "undeterrable" threat, and the suggestion that he does has distracted attention from his truly outstanding characteristic, which is recklessness. In reality Saddam has an unbroken track record of attacking victims that appeared to be weak and vulnerable, not those strong enough to respond by pulverizing him. He has gotten in trouble in the past not so much because he has no fear, but because he has no judgment. This is not quite the same as being "undeterrable," but it trends in the same direction, a fact that deserves more emphasis than it has received. Saddam may be a special case even among the world's rogues and desperados, because his conduct is so non-linear that one dare not wait to see what will happen next. If Saddam now finds himself in the cross-hairs of U.S. war planners, that is the reason, and it is one far more deserving of serious debate than whether a "smoking gun" of sufficient caliber has been produced or not.