Deterrence
Deterrence
As the release and utilization of energy from atomic nuclei have challenged and intrigued physical scientists, so behavioral and social scientists have been intrigued and challenged by the intrusion of this energy into the domain of their concern. Awareness of the potential destructiveness of weapons employing nuclear energy has prompted extensive consideration of their impact on international relations.
In its contemporary usage, the concept “deterrence” refers to hypothesized effects of nuclear weapons technology on the set of alternatives from which national policy makers choose their courses of action. By extension, these “effects” affect the conduct of international relations.
The set of alternatives from which national leaders make their choices has traditionally included among its elements the “resort to war” as an instrument of national policy; the hypothesized effects of nuclear weapons are relevant to this subset of foreign policy alternatives.
”Deterrence” refers to the attempt by decision makers in one nation or group of nations to restructure the set of alternatives available to decision makers in another nation or group of nations by posing a threat to their key values. The restructuring is an attempt to exclude armed aggression (resort to war), from consideration.
The fundamental deterrence hypothesis is: If the threat to values is sufficiently large, the exclusion of armed aggression from consideration is probable.
This hypothesis, taken together with a subsidiary hypothesis—nuclear weapons pose a sufficiently large threat to values—yields the deduction: Nuclear weapons make probable the rejection of armed aggression as a potential policy alternative.
The ubiquity of this syllogism in the deterrence literature (Brody I960; Lefever 1962, pp. 313–332; Halperin 1963, pp. 133–184) argues for the examination of the postulates on which it is founded. Three central assumptions appear to underlie this syllogism; they may be classified under the following themes: (1) the rationality of decision makers; (2) the unidimensionality of threat and of response to threats; and (3) the constancy of sets of policy alternatives (see Deutsch 1963, pp. 71–72, for a critique of a somewhat different set of deterrence theory assumptions).
The assumption of rationality. The rationality of decision makers posited in the deterrence literature is both a norm against which behavior can be evaluated and a prescriptive guide to choice. The rational decision maker, in deterrence theory, is presumed to avoid the resort to war in those situations in which the cost anticipated from aggression is greater than the gain expected from such an action.
This notion of rationality concentrates on avoidance behavior; it predicts the rejection of alternatives where cost exceeds gain. Empirical studies on foreign policy decision making are not abundant, but those that have been done raise doubts about this characterization of the policy process (Snyder & Paige 1958; Holsti 1962). In the light of research on domestic and foreign policy making, this postulate of deterrence theory is of dubious validity.
Conceptions of threat. The fundamental deterrence syllogism contains implicit assumptions about the nature of threat and about the relationship of threat to deterrence.
Threat is presumed to be a simple function of destructive capacity; the greater the destructive capability, the greater the threat. A more complex view of threat (for example, Singer 1958) calls this conception into question unless “destructive capacity” is construed very broadly—beyond numbers of weapons, warhead size (yield), and accuracy.
Experiments on the relationship of power to threat indicate that the ambiguity (or, conversely, the clarity) of the threat is closely related to the amount of threat experienced (Cohen 1959).
It has been suggested elsewhere (Brody 1963, pp. 696–697) that the threatening interaction can be conceived of as being determined by three factors: (1) perception by one party of the other party’s hostile intentions; (2) perception of the other party’s capability of inflicting damage to the perceiver; and (3) the credibility of the other party’s declaratory policy. If threat inhered only in capability (and we ignored hostility and credibility), we would conclude that adversaries and allies are equally threatened by the same weapons systems.
Complex conceptions of threat call into question not only the proposition that threat varies uniformly with destructive power but also many of the assumptions about the relationship of threat to deterrence. The literature is replete with suggestions that the effectiveness of deterrence is a direct function of the amount of destructive capability. Wohlstetter (1959) has refined this conception by pointing out that deterrence is more properly conceived of as a function of the amount of capability potentially remaining after an attack has been absorbed. Both of these conceptions assume that the threatened decision maker will be “deterred,” that is, that he will abandon even the consideration of the course of action that worried the threatener.
”Credibility” has received attention from deterrence theorists (Kaufmann 1956, pp. 12–38), but as a quality of weapons rather than of relations among nations. However, the possibility of an aggressive response to a credible threat receives much less attention (for example, Kahn 1963). Psychologists, on the other hand, have often found aggressive responses to threat (for example, McNeil 1959). This suggests at least the potential for such responses in threatening international situations.
Milburn, drawing on psychological research, proposes that we characterize threats on a number of dimensions (for example, symbolic–concrete and clear–vague); however, the relationship between types of threats, characterized on these dimensions, and the inhibition of behavior (deterrence) or excitation of behavior (provocation) is without empirical research, despite the salience of such knowledge for deterrence theory.
Availability of policy alternatives. Implicit also in much of the literature on deterrence is the assumption that alternatives to the resort to war are available to and perceived by decision makers, irrespective of the international situation.
The validity of this proposition is difficult to establish: the historical record is rich with examples of national leaders who, in intense crises, “saw no way out” and for whom war became the only viable alternative. On the other hand, despite extremely intense crises, decision makers in the nuclear-armed nations apparently have not felt that their policy alternatives were reduced to one—war.
Contradictory hypotheses can be entertained to resolve this paradox: Because of their destructiveness, nuclear weapons may have transformed the international system, thus making the prenuclear historical examples simply inapplicable. However, it is equally plausible that the international system has moved onto a plateau of high intensity (McClelland 1961)—the cold war—and that increases in tension (relative to this base), comparable to historical crises, have not yet been experienced by leaders in one nuclear nation when confronted by another. Which hypothesis will stand the test of research cannot be forejudged, but an answer is needed to strengthen the conceptual foundations of deterrence theory.
Deterrence strategies. Despite the lack of confirmation of the premises on which elemental deterrence theory is based, there is widespread a priori acceptance of them. The dialogue, which has produced a voluminous literature, has largely been concerned with how best to deter; thus, the debate has been primarily strategic rather than social scientific.
An important impetus to this debate has been the rapidly changing weapons technology; each new capability has found spokesmen arguing the necessity of including it in the considerations affecting strategic thought. Technology has tended to lead strategy, bringing an evanescent quality to the deterrence literature.
The debate among deterrence strategists can be characterized by examining the various positions along three dimensions: (1) the mission of the deterrent; (2) the means by which deterrence is to be accomplished; and (3) the values threatened and to be threatened.
There is little disagreement that a goal of foreign policy is the dissuasion of other nations from committing aggression of any kind—from strategic nuclear attack to guerrilla warfare. Debate arises over how much of this spectrum can be deterred with nuclear weapons.
Glenn Snyder (1961) provides a useful distinction between the missions of denying access to territory and of punishing aggression (that is, of retaliation ); weapons appropriate to one mission may not be suited to the other. Thus, for example, the mission of denying western Europe to Soviet forces, it is argued, requires different weapons than does the mission of retaliating against the Soviet homeland, should the Soviet leaders choose to attack. The counter to this argument, stemming from the strategic doctrines of Douhet (Brodie 1959), asserts that the massive threat inherent in nuclear retaliatory capability will deter tactical as well as strategic aggression.
Those who argue for specific weapons for specific missions—the strategy usually called “graduated deterrence”—point to the ineffectiveness of strategic bombing as a deterrent in World War ii (Blackett 1962) and to the reduced credibility of an all-purpose deterrent after the Soviet Union emerged as a nuclear power.
This debate overlaps the dialogue about the means by which deterrence can best be accomplished. The strategists who advocate graduated deterrence generally argue for the limitation of strategic capability at the minimum needed to deter (Morgenstern 1959). The logic of this position relies heavily on the invulnerability to attack of individual units of the deterrent force. The critics of minimum deterrence point out, however, that the continuation of this invulnerability in view of the growth of weapons technology is too uncertain for so fundamental an element of policy (Kahn I960; 1963). The advocates of minimum deterrence argue that sustained effort in producing weapons beyond the minimum (in an attempt to guarantee at least “statistical invulnerability” of the force as a whole) is itself a stimulus to the search for countermeasures and to the uncontrolled stockpiling of arms, that is, to arms races,
Proponents of graduated deterrence argue that the absence of military capability to counter a particular lower-level or nonnuclear threat, for example, insufficient conventional forces to deny territory in western Europe to the Soviet Army, creates an unstable situation fraught with the danger of escalation to strategic nuclear war. It is in escalation, that is, in resort to weapons with much greater destructive capacity than the weapons employed by the attacking side, that deterrence theorists see the greatest likelihood of limited wars becoming general nuclear wars (Schelling I960; Halperin 1963). Moreover, the expansion of limited conflicts is often seen as the most probable cause of general war.
Concentration on the deterrence of general war has led to a debate about what is the best object of threat: Is the threatened destruction of cities more effective than the threatened destruction of military targets in precluding resort to war?
The dual nature of weapons—they can be used to fight as well as to threaten—has brought an element of confusion to the debate. If a war is to be fought, response weapons capable of destroying military capability may be most effective in limiting damage to targets of high value to the responding nation (Kahn 1963). On the other hand, it is contended that producing this amount of weaponry (because there are many more well-defended military targets than civilian targets) could create an unstable arms race that would make war more likely.
The advocates of minimum deterrence have tended to opt for targeting population and industrial centers; the opposition to this point of view has tended to argue for preserving the option of retaliating against any target, civilian or military. The second policy seems to be characteristic of United States military posture; the first seems to have been adopted by the Soviet Union.
Deterrence and international relations. The lively debates among deterrence strategists has had a salutary effect on the field of international relations. Social scientists have expressed uncertainty about the validity of the principles on which deterrence theory rests and some skepticism about assertions concerning the way nations act and are likely to act; from this doubt and questioning, professional students of international politics have begun to think of the relationship of military technology to foreign policy as a significant area of research. Moreover, the subject matter has brought scholars from all the social sciences together and has forced interdisciplinary communication.
The strategic debates will continue as military technology continues to change, but the conceptual foundations laid by the work of concerned social scientists are the beginnings of the reintegration of military strategy into the study of international relations; in this context we can expect the patient development of an empirical theory of deterrence.
Richard A. Brody
[See alsoNuclear War; Strategy.]
BIBLIOGRAPHY
Blackett, Patrick M. S. 1962 Studies of War: Nuclear and Conventional. New York: Hill & Wang.
Brodie, Bernard 1959 Strategy in the Missile Age. Princeton Univ. Press.
Brody, Richard A. 1960 Deterrence Strategies: An Annotated Bibliography. Journal of Conflict Resolution 4:443–457.
Brody, Richard A. 1963 Some Systemic Effects of the Spread of Nuclear Weapons Technology: A Study Through Simulation of a Multi-nuclear Future. Journal of Conflict Resolution 7:663–753.
Cohen, A. R. 1959 Situational Structure, Self-esteem, and Threat Oriented Reactions to Power. Pages 35–52 in Dorwin Cartwright (editor), Studies in Social Power. Ann Arbor: Univ. of Michigan, Institute for Social Research.
Deutsch, Karl W. 1963 The Nerves of Government: Models of Political Communication and Control. New York: Free Press.
Halperin, Morton H. 1963 Limited War in the Nuclear Age. New York: Wiley. ? See especially the bibliography on pages 133–184.
Holsti, Ole R. 1962 The Belief System and National Images: A Case Study. Journal of Conflict Resolution 6:244–252.
Kahn, Herman (1960) 1961 On Thermonuclear War. 2d ed. Princeton Univ. Press.
Kahn, Herman 1963 Strategy, Foreign Policy, and Thermonuclear War. Pages 43–70 in Robert A. Goldwin (editor), America Armed: Essays on United States Military Policy. Chicago: Rand McNally.
Kaufmann, William W. (editor) 1956 Military Policy and National Security. Princeton Univ. Press.
Lefever, Ernest W. (editor) 1962 Arms and Arms Control: A Symposium. New York: Praeger. ? See especially the bibliography on pages 313–332.
McClelland, Charles A. 1961 The Acute International Crisis. World Politics 14:182–204.
McNeil, Elton B. 1959 Psychology and Aggression. Journal of Conflict Resolution 3:195–293.
Milburn, Thomas W. 1959 What Constitutes Effective Deterrence? Journal of Conflict Resolution 3:138–145.
Morgenstern, Oskar 1959 The Question of National Defense. New York: Random House. ? A paperback edition was published in 1961 by Vintage.
Schelling, Thomas C. 1960 The Strategy of Conflict. Cambridge, Mass.: Harvard Univ. Press.
Singer, J. David 1958 Threat-perception and the Armament-tension Dilemma. Journal of Conflict Resolution 2:90–105.
Singer, J. David 1962 Deterrence, Arms Control, and Disarmament. Columbus: Ohio State Univ. Press.
Snyder, Glenn H. 1961 Deterrence and Defense: Toward a Theory of National Security. Princeton Univ. Press.
Snyder, Richard C.; and Paige, Glenn D. 1958 The United States Decision to Resist Aggression in Korea: The Application of an Analytical Scheme. Administrative Science Quarterly 3:341–378.
Wohlstetter, Albert 1959 The Delicate Balance of Terror. Foreign Affairs 37:211–234.