Capability Requirements

Two related "rules" have generally dominated national security policy: the para helium doctrine—"if you want peace, prepare for war"—and the premise that security is a direct function of military superiority vis-a-vis prospective enemies. Whatever the merits of the para helium doctrine (the frequency of wars prior to 1945 suggests that it may not be a reliable or sufficient guide in all

288 Weapons, War, and Political Influence

situations), the almost irresistible conventional wisdom that argues that deter­rence can be enhanced merely by piling up more and better weapons than the opponent can amass must be qualified in a number of respects.

Invulnerability An important element of stable deterrence is a mutual second-strike capacity. The speed, range, and destructive capacity of modern weapons may provide a potential attacker with the opportunity and the tempta­tion to destroy the adversary's retaliatory capacity with a surprise attack. If a nation's leaders believe that a surprise attack will permit a quick victory without much likelihood of retaliation because the opponent's weapons can be destroyed before they are used, the latter's deterrent posture is hardly credible. Irrespective of the other attributes, weapons that are a tempting target for a first strike may prove to be no deterrent at all. The concentration of American naval power at Pearl Harbor in 1941 provided Japan with an irresistible temptation to try to gain its objectives with a sudden knockout blow, and the neatly arrayed aircraft on Egyptian airfields gave Israel an opportunity to ensure victory in the Six-Day War of 1967 within the first few hours. Thus, deterrent effect is a function _t l not of total destructive capacity, but of reliable weapons capable of surviving a t/V surprise attack.

Nor do vulnerable forces satisfy the requirement of stability, because, by failing to provide decision makers with the capacity to delay response, they require a finger to be kept on the trigger at all times. Knowledge that the opponent can launch a crippling surprise attack reduces decision time and in­creases pressure to launch a preemptive strike at the first signal (which may turn out to be false) that such an attack is imminent. When both nations' deterrent forces are vulnerable, the situation is even less stable, as neither side can afford to delay. Each may prefer to back off, but neither can be certain of not having its "rationality" exploited. A delay of hours, or even minutes, can make the difference between being able to retaliate and having one's military capabilities destroyed. Compressed decision time and the need for a "hair trigger" on retalia­tory forces significantly increase the probabilities of accidental war.

Conversely, invulnerable strategic forces—those that cannot be elimi­nated, even by the most severe attack that the enemy can mount—may mitigate some of the more severe time pressures attending a crisis. Knowledge that one's forces are secure reduces the motive to "shoot first and ask questions later." The temptation to launch a first strike should diminish as the certainty and probable costs of devastating retaliation increase. Equally important, when retal­iatory systems are invulnerable, the incentive to undertake a preemptive attack in the absence of complete information (as, for example, in case of a nuclear explosion of unknown origin) declines as the ability to delay response increases decision time.

Survival capability of deterrent forces can be enhanced by a number of methods. An increase in numbers can, at least temporarily, make it more difficult for the attacker to succeed in a first strike. This method is relatively crude,

J9 Weapons, War, and Political Influence

and it will be effective only if the adversary does not increase its forces propor­tionately. The search for numerical superiority may decrease vulnerability in the short run, but its long-term consequences are almost certain to be an arms race that leaves neither side more secure. Dispersal of forces at home and in overseas bases may also provide some protection, but this alternative becomes less attractive as delivery systems become more accurate and as the political costs of foreign bases increase. "Hardening" retaliatory weapons (such as land-based missiles) by placing them in underground silos, although relatively expen­sive, can provide adequate protection against all but a direct strike. Assuming a specified probable error in the accuracy of attacking missiles, hardening re­quires the attacker to expend more weapons on each target, thereby reducing the probability of a crippling first strike. Expectations that missiles in protected silos would prove to be the "ultimate" retaliatory weapons have proved mistaken, however, because reconnaissance satellites can find them and, even more impor­tantly, because missile guidance systems have become increasingly accurate. Multiple independently targetable reentry vehicles (MIRVs) are so accurate that 50 percent of the warheads can be expected to land within a few hundred meters of the target. Research and development work on independently targetable war­heads that can be maneuvered in flight (MARVs) may ultimately reduce that figure to 50 meters or less. Thus, although bigger warheads can threaten the invulnerability of retaliatory forces, the far more salient danger arises from the increasing accuracy of missile systems.²⁴ Placing retaliatory sources at the maxi­mum possible distance from a potential enemy ensures their survival only as long as the gap in distance is not closed by longer-range delivery systems. A further measure of protection can be provided by concealment, but this method is already somewhat vulnerable to advances in the technology of detection. American U-2 flights over the Soviet Union proved that high-altitude photography can yield considerable intelligence information. Orbiting "spy" satellites have been even more effective than the U-2, without incurring any of the political costs of manned overflights. Finally, a nation may seek to protect its retaliatory forces by adopting a fire-on-warning policy. For reasons discussed above, however, doing so would create a highly unstable situation.

At present, the most reliable method of decreasing vulnerability is mobil­ity. Missile-launching submarines have become major components of American and Soviet defense forces, and they are an important element in the British and French nuclear deterrent. Important characteristics of this weapon system are these: (1) it combines high mobility with the capabilities for dispersal, dis­tance, and concealment; (2) unlike missile sites or air bases located near cities,

²⁴ According to the "cube root law," the blast effect increases only as the cube root of the increase in yield. Hence, an increase in accuracy will threaten protected targets much more than will an increase in explosive power. For this reason, it is somewhat misleading to assume a linear relationship between "throw weight" (payload capacity of missiles) and ability to threaten retaliatory forces. The "throw weight" controversy was triggered off by the 1974 Vladivostok interim agreement and intensified by the subsequent SALT II Treaty of 1979, both of which permitted the Soviet Union to keep 308 SS-18 multiple-warhead missiles.

290 Weapons, War, and Political Influence

it provides the enemy with no incentive to attack major population centers; (3) it does not require foreign bases; and (4) it may remain beyond striking distance of its targets (communicating reassurance), but it can rapidly be brought into firing position without losing its invulnerability.²⁵

One point should be emphasized, however. The ability of the invulnera­ble deterrent forces to delay response may be a necessary, but is not a sufficient, factor to eliminate the incentives to strike first and to ensure crisis-stable deter­rence. None of the nations in the 1914 crisis had the ability to unleash a rapid destructive blow, crippling the retaliatory capabilities of the adversary. But in the tense days preceding the outbreak of general war, decision makers in Berlin, St. Petersburg, Paris, and London increasingly attributed to their potential ene­mies both the ability and the intent to do so. The penalties for delay were perceived to be too high. The ability to delay response is therefore not likely to contribute to crisis management unless policy makers perceive that the risks of acting in haste are greater than those of using a strategy of delay and, equally important, unless they are willing to attribute the same preferences to the adversary's leader­ship.

Force LevelsThe theory of a linear relationship between military capa­bility and deterrent effect has been questioned as nuclear arsenals have reached the "overkill" range. Whether the capacity of nuclear weapons to destroy any existing society has tended to make national leaders more cautious in considering decisions that might precipitate a nuclear war has been neither proved nor disproved, but it is at least plausible; the proposition that the capacity to destroy any potential adversary or coalition of opponents five, ten, or 100 times over increases caution proportionately seems untenable. The case for overwhelming strategic superiority was more persuasive when delivery systems were limited to manned bombers, which are vulnerable to surprise attack. Sheer numerical superiority provided some short-run protection against a crippling and decisive first strike. But, as indicated above, greater protection at lower cost (politically and in stability) can be achieved by mobile invulnerable deterrent systems.

FlexibilityPerhaps the most serious limitation to the theory of a linear

^v relationship between destructive capability and deterrent effect lies in the ability

to deter aggression at many levels of intensity. One aspect of the issue has

been discussed earlier—the credibility of threatening "massive retaliation" to

deter limited aggression.

Before 1945, a single weapons system could generally be counted upon to perform multiple tasks. For example, a strong French army could be deployed

²⁵ Because submarine-launched ballistic missile forces are the most stable element of deter­rence, any technological breakthrough in antisubmarine warfare capabilities that threatened their invulnerability would be highly destabilizing. A fuller discussion of this issue may be found in Stockholm International Peace Research Institute, Tactical and Strategic Antisubmarine Warfare (Stock­holm, Sweden: Almqvist & Wiksell, 1974).

291 Weapons, War, and Political Influence

to defend the eastern frontiers against Germany; the same army could, with little modification, also pacify colonial areas. Similarly, the British navy could serve as an instrument for multiple goals—a deterrent against attack on the home island, protection of shipping and commerce, or destruction of an enemy fleet in war.

Whether nuclear arsenals are capable of serving multiple defense re­quirements is more open to question. For example, can the same weapons to be used to deter an attack against one's home territory, to dissuade adversaries from launching a limited war, and to prevent or cope with various types of limited threats?²⁶ During the years immediately after World War II, the deterrent function of nuclear weapons was assumed to be self-evident. The invasion of South Korea by Communist forces called this premise of the Truman administra­tion into question. The defense policy of the Eisenhower administration placed considerable emphasis on the deterrent effectiveness of strategic weapons across a broad spectrum of situations. This line of reasoning underlay British defense policies of the 1950s, as well as those of France since the 1960s. Rejecting the "massive retaliation" doctrine of the Eisenhower administration in favor of a policy of "flexible response," Presidents Kennedy and Johnson actively sought to restore a balance between nuclear and conventional forces. With very indifferent success, they also attempted to persuade NATO allies in Europe to focus their resources on forces of the latter type. For fiscal and domestic political reasons, the Nixon and Ford administrations moved toward a reduction of ground forces and back toward greater reliance on the deterrent effects of strate­gic weapons. According to the "Nixon Doctrine," local forces are to provide the bulk of ground forces. Following the Iran hostage crisis and the Soviet invasion of Afghanistan, the Carter administration announced plans to enhance conventional forces. The Reagan administration is both increasing conventional forces and pressing NATO allies to follow suit.

Defense analysts have generally accepted the need for flexible forces. ' The credibility of a threatened nuclear response to limited provocation may be quite small and will diminish each time limited aggression goes unchallenged. A commitment to meet every provocation automatically with a massive nuclear response denies oneself the possibility for recalculating costs and gains with changed circumstances. Moreover, nuclear retaliation is of questionable validity, either militarily or morally, as a response to limited aggression.

The threat of strategic retaliation may well prove effective against an unambiguous attack against targets of high value. Soviet and American strategic forces have effectively deterred either one from launching a direct attack on the other (assuming that the motivation to do so may in fact have existed). But even in Europe, an area where American alliance commitments are presum­ably the most credible, the nuclear forces have proved inadequate to deter peri-

²⁶ This distinction between three levels of deterrence and its implications are developed in detail in George and Smoke, Deterrence in American Foreign Policy.

292 Weapons, War, and Political Influence

odic Soviet attempts to alter the status quo by coercive means—for example, in West Berlin. Nor has a combination of American strategic forces and alliance commitments been sufficient to deter limited probes in other areas or to deal with such issues as the hostages in Iran or the Soviet invasion of Afghanistan. Certainly the threat of nuclear retaliation must be regarded as of very limited utility in areas where frontiers are ambiguous; where the credibility of commit­ments to allies may be suspect; where regimes are unstable; where the difference between genuine domestic revolutionary movements, private armies of dissident domestic factions, and foreign guerrilla forces is often blurred; and where clan­destine aid across frontiers is difficult to identify and even harder to prevent.

Finally, those who intend to challenge the status quo usually have various options for doing so. A defender unable to call upon responses other than strategic threats is unlikely to be successful. For example, even a virtual American monopoly of nuclear weapons in 1950 did not prevent the invasion of South Korea by Communist forces from the north. Once the invasion occurred, had a threat been made to devastate Moscow or Peking unless North Korean forces withdrew beyond the 38th parallel, it might well have been regarded as a bluff. To make the threat without carrying it out would reduce the future credibility of the stategic deterrent; to carry out the threat would have resulted in a major escalation of a limited war to an unlimited one. The American and United Nations response to the Korean invasion, a limited one relying on conventional forces, did not result in a complete victory; but it did restore the frontier between the two Koreas to approximately the pre-1950 position without escalation of the conflict geographically (fighting remained confined to the Korean peninsula as supply bases in Manchuria and Japan remained untouched) and militarily (both sides abstained from the use of nuclear weapons).²⁷

One caveat is worth mentioning. A broad range of available capabilities is not an end in itself. Nor does it ensure that, from the wide spectrum of options it makes possible, choices will be made wisely. In 1954, some six months after Secretary of State Dulles's "massive retaliation" speech, the Eisenhower administration decided against intervention in Indochina, partly on the grounds that American conventional forces were insufficient for the task. In response to the logical and political shortcomings of massive retaliation—these had been recognized by Dulles less than four years after the 1954 speech—the Kennedy and Johnson administrations undertook a large buildup of conventional forces to redress existing imbalances. But the availability of multiple military options also made it possible to become committed, step by almost imperceptible step, to a tremendously costly and ultimately unsuccessful war in Vietnam. The value of flexible capabilities is thus no greater than the wisdom with which they are deployed.

²⁷ However, the unwise decision to pursue North Korean forces back across the 38th parallel did eventually result in expansion of the war, as Chinese armies entered the conflict in November 1950. As a result, the war developed into a bloody stalemate near the 38th parallel for two and a half years.

293Weapons, War, and Political Influence

Another aspect of the relationship between weapons and influence has been identified by Thomas Schelling, who has distinguished between (1) deter­rence, the ability to prohibit certain policies (negative influence) on the part of enemies; and (2) compellance or coercive diplomacy, the capacity to persuade the adversary to undertake specified actions (positive influence).²⁸ American strategic capabilities may have deterred the Soviet Union from overt large-scale aggression in Europe, but attempts to compel North Vietnam to cease supplying its forces in South Vietnam and those of the Viet Cong by bombing transportation routes indicate the difficulty of achieving this type of influence even with conventional weapons. Similarly, Israeli commando raids may deter some types of Arab behav­ior, but they have not been successful in compelling Arab leaders other than the late Anwar Sadat to negotiate face to face with Tel Aviv. Chinese and Soviet attacks on each other's frontier positions may serve some deterrent functions, but they are not an effective way of compelling the adversary to renounce ideolog­ical "heresies" or to acknowledge the other as the leading communist nation. In none of these cases is there reason to believe that threats to use nuclear weapons would enhance the prospects for successful coercion.

Поиск по сайту: