Wednesday, August 5, 2009

INR 2002: Waltz Article - Realist Thought and Neorealist Theory

Realist Thought and Neorealist Theory

Source: Journal of International Affairs, Spring/Summer90, Vol. 44 Issue 1, p21, 17p

Exploring various ways to forward the study of international politics was one of William T.R. Fox’s many interests. In 1957, he organized a series of seminars that brought together a number of established scholars, among them Paul Nitze, Hans Morgenthau and Charles Kindleberger, along with such younger scholars as Robert W. Tucker, Morton Kaplan and Martin Wight, to discuss problems in the study of international-political theory and its relation to the behavior of states. A volume edited and co-authored by Bill was the tangible product of the colloquinum.(n2) As one of the many students and colleagues who benefitted from Bill’s ideas, encouragement, and support, I offer this essay as a small contribution toward clarifying some problems in the framing and applying of international political theory.

I begin by looking at a theoretical breakthrough in a related field: economics. Realists and neorealists represent two of the major theoretical approaches followed by students of international politics in the past half century or so. They encountered problems similar to those the Physiocrats began to solve in France in the middle of the eighteenth century. Students of international politics have had an extraordinarily difficult time casting their subject in theoretical terms. Looking first at an example of comparable difficulties surmounted in a related field may be instructive.

How Economic Theory Became Possible
Difficulties common to earlier economists and twentieth-century political scientists are revealed by examining Sir Josiah Child’s A New Discourse, written mainly in the years 1668 to 1670.(n3) Child dealt with a striking question. Why, he wondered, did the prosperity of the Dutch surpass that of the English? In casting about for an answer, he seized on what seemed to be a compelling fact: namely, that the Dutch rate of interest had been lower than the English rate. The reasoning used to establish the causal role of the rate of interest is correlative and sequential. Child tried to show that the prosperity of various countries varies inversely with prevailing rates of interest. He then established the causal direction by arguing that the expected changes in the level of prosperity followed upon changes in rates of interest.

Child’s work is the kind of pre-theoretical effort that provides stimulus to, and material for, later theories. That is its merit. It is, however, the kind of work that can neither provide satisfactory explanations nor lead to the construction of theory. We can profit by noticing why this is so. Child tried to establish a necessary relation between the rate of interest and the level of prosperity. Other economists picked different factors as their favorite causes--the accumulation of bullion, the fertility of the population or the soil, the industry of the people, the level of rents, or whatever. But none was able to show why the relation between the chosen factor or factors and the condition to be accounted for necessarily held. Child, for example, could not supply an answer to this now obvious question: Why doesn’t a rise in interest rates attract capital, ultimately lowering its price as with commodities? He could not say whether the association he claimed to have found was causal or coincidental. He could not say whether other factors in play may have caused interest rates and national prosperity to move in opposite directions. Innumerable explanations for the observed relation were available. Pre-physiocratic economists could only cast about for sequences and associations that seemed to pertain within or across countries. They could at best hope to formulate plausible explanations of particular outcomes. They had no way of relating the parts of an economy to one another and to the economy as a whole.

The first step forward was, as it had to be, to invent the concept of an economy as distinct from the society and the polity in which it is embedded. Some will always complain that it is artificial to think of an economy separate from its society and polity. Such critics are right. Yet the critics miss the point. Theory is artifice. A theory is an intellectual construction by which we select facts and interpret them. The challenge is to bring theory to bear on facts in ways that permit explanation and prediction. That can only be accomplished by distinguishing between theory and fact. Only if this distinction is made can theory be used to examine and interpret facts.

In the pre-theoretic era of economics, more and more information became available in the form of reported, or purported, facts, and more and more attempts were made to account for them. But differences of explanation remained unreconciled and explanations of particular processes and outcomes did not add up to an understanding of how a national economy works. In a remarkable survey in which the historical development, the sociological setting, and the scientific qualities of economic thought are brought together, Joseph Schumpeter described the best economic literature of that earlier time as having "all the freshness and fruitfulness of direct observation." But, he added, it also "shows all the helplessness of mere observation by itself."(n4) Information accumulated, but arguments, even perceptive ones about propositions that might have been developed as theories, did not add up to anything more than ideas about particulars occasioned by current controversies.

Child was better then most economists of his day, although not as good as the best. The most creative economists were frustrated by the condition that Schumpeter described. The seventeenth-century economist Sir William Petty, for example, felt the frustration. Schumpeter described him as creating "for himself theoretical tools with which he tried to force a way through the undergrowth of facts."(n5) To eliminate useless and misleading "facts" was an important endeavor, but not a sufficient one. What blocked the progress of economic understanding was neither too little nor too much knowledge but rather the lack of a certain kind of knowledge.

The answers to factual questions pose puzzles that theory may hope to solve and provide materials for theorists to work with. But the work begins only when theoretical questions are posed. Theory cannot be fashioned from the answers to such factual questions as: What follows upon, or is associated with, what. Instead, answers have to be sought to such theoretical questions as these: How does this thing work? How does it all hang together? These questions cannot usefully be asked unless one has some idea of what the "thing" or the "it" might be. Theory becomes possible only if various objects and processes, movements and events, acts and interactions, are viewed as forming a domain that can be studied in its own right. Clearing away useless facts was not enough; something new had to be created. An invention was needed that would permit economic phenomena to be seen as distinct processes, that would permit an economy to be viewed as a realm of affairs marked off from social and political life.

This the Physiocrats first achieved. Francois Quesnay’s famous economic table is a picture depicting the circulation of wealth among the productive and unproductive classes of society, but it is a picture of the unseen and the unseeable.(n6) Certain cycles are well-known facts of economic life--cycles of sowing and harvesting, of mining, refining, forging, and manufacturing. But such a direct simplification of observable processes is not what Quesnay’s table presents. It presents, instead, the essential qualities of an economy in picture form. The

Physiocrats were the first to think of an economy as a self-sustaining whole made up of interacting parts and repeated activities. To do so, they had to make radical simplifications--for example, by employing a psychology that saw people simply as seeking the greatest satisfaction from the least effort. They invented the concepts they needed. Their notion of a "social product" can well be described as the intellectual creation of the unobservable and the nonexistent. No one can point to a social product. It is not an identifiable quantity of goods but is instead a concept whose validity can be established only through its role in a theory that yields an improved understanding of the economy.

The Physiocrats developed concepts comprising innumerable particularities and contingencies without examining them. Among these concepts were the durable notions of distribution and circulation. The quaint and crude appearance of some physiocratic ideas should not obscure the radical advance that their theory represented. Economists had found it hard to get a theoretical hold on their subject. In pre-physiocratic economics, as Schumpeter said, "the connecting link of economic causality and an insight into the inner necessities and the general character of economics were missing. It was possible to consider the individual acts of exchange, the phenomenon of money, and the question of protective tariffs as economic problems, but it was impossible to see the total process which unfolds itself in a particular economic period. Before the Physiocrats appeared on the scene, only local symptoms on the economic body, as it were, had been perceived." Only the parts of an economy could be dealt with. It was therefore necessary again in Schumpeter’s words, "to derive an explanatory principle from each separate complex of facts--as it were in a gigantic struggle with them--and it was at best possible merely to sense the great general contexts."(n7)

International Politics: Beyond the Theoretical Pale
What the Physiocrats did for economics is exactly what Raymond Aron and Hans Morgenthau, two of the most theoretically self-conscious traditional realists, believed to be impossible for students of international politics to accomplish. Aron drew a sharp distinction between the study of economics and the study of international politics. The latter he assigned to the category of history, which deals with unique events and situations, and of sociology, which deals with non-logical actions and searches for general relations among them. In contrast to economics, Aron said international politics suffers from the following difficulties:

Innumerable factors affect the international system and no distinction can be made between those that are internal and those that are external to it.
States, the principal international actors, cannot be endowed with a single aim.
No distinction can be drawn between dependent and independent variables.
No accounting identities-such as investment equals savings-can be devised.
No mechanism exists for the restoration of a disrupted equilibrium.
There is no possibility of prediction and manipulation with identified means leading to specified goals.(n8)
Do the reasons cited eliminate the possibility of devising a theory of international politics? If so, then economics would have been similarly hampered. Aron did not relate obvious differences between economics and politics to the requirements of theory construction. He merely identified differences, in the confident belief that because of them no international-political theory is possible.

Morgenthau’s theoretical stance is similar to Aron’s. Morgenthau dealt persuasively with major problems and with issues of enduring importance. He had the knack of singling out salient facts and constructing causal analyses around them. He sought "to paint a picture of foreign policy" that would present its "rational essence," abstracting from personality and prejudice, and, especially in democracies, from the importunities of popular opinion that "impair the rationality of foreign policy."(n9) He was engaged, as it were, "in a gigantic struggle" with the facts, seeking "to derive an explanatory principle" from them. Like Petty, he forged concepts that might help him "force a way through the undergrowth of facts," such concepts as "national interest" and "interest defined as power." Like Child, Morgenthau and other realists failed to take the fateful step beyond developing concepts to the fashioning of a recognizable theory.

Morgenthau described his purpose as being "to present a theory of international politics."(n10) Elements of a theory are presented, but never a theory. Morgenthau at once believed in "the possibility of developing a rational theory" and remained deeply skeptical about that possibility. Without a concept of the whole, he could only deal with the parts. As is rather commonly done, he confused the problem of explaining foreign policy with the problem of developing a theory of international politics. He then concluded that international political theory is difficult if not impossible to contrive.(n11) He was fond of repeating Blaise Pascal’s remark that the history of the world would have been different had Cleopatra’s nose been a bit shorter, and then asking, "how do you systemize that?"(n12) His appreciation of the role of the accidental and the occurrence of the unexpected in politics dampened his theoretical aspirations.

Neorealism’s response is that, while difficulties abound, some that seem most daunting lie in misapprehensions about theory. Theory obviously cannot explain the accidental or account for unexpected events. Theories deal in regularities and repetitions and are possible only if these can tee identified. As a realist, Morgenthau maintained "the autonomy of politics," but he failed to develop the concept and apply it to international politics.(n13) A theory is a depiction of the organization of a domain and of the connections among its parts.(n14) A theory indicates that some factors are more important than others and specifies relations among them. In reality, everything is related to everything else, and one domain cannot be separated from others. Theory isolates one realm from all others in order to deal with it intellectually. To isolate a realm is a precondition to developing a theory that will explain what goes on within it. The theoretical ambitions of Morgenthau, as of Aron, were forestalled by his belief that the international political domain cannot be marked off from others for the purpose of constructing a theory.

In summarizing Aron’s argument, I have put the first three points in sequence because they are closely interrelated. The single word "complexity" suggests the impediment that concerns him. If "economic, political, and social variables"(n15) enter into the international system, as surely they do, if states have not one but many goals, as surely they have, if separating dependent from independent variables and distinguishing effects from causes is an uncertain undertaking, as surely it is-then one can never hope to fashion a theory.

Complexity, however, does not work against theory. Rather, theory is a means of dealing with complexity. Economists can deal with it because they long ago solved Aron’s first problem. Given the concept of a market-a bounded economic domain-they have been able to develop further concepts and draw connections among them. Because realists did not solve the first problem, they could not satisfactorily deal with the next two. Men have many motives. If all or very many of them must always be taken into account, economic theory becomes impossible. "Economic man" was therefore created. Men were assumed to be single-minded, economic maximizers. An assumption or a set of assumptions is necessary. In making assumptions about men’s (or states’) motivations, the world must be drastically simplified; subtleties must be rudely pushed aside, and reality must be grossly distorted. Descriptions strive for accuracy; assumptions are brazenly false. The assumptions on which theories are built are radical simplifications of the world and are useful only because they are such. Any radical simplification conveys a false impression of the world.

Aron’s second and third points must be amended. Actors cannot realistically be endowed with a single aim, but we can only know by trying whether or not they can usefully be so endowed for purposes of constructing a theory. Political studies are not different from other studies in the realm of human affairs. We can make bold assumptions about motives, we can guess which few of many factors are salient, we can arbitrarily specify relations of dependence and independence among variables. We may even expect that the more complex and intricate the matters being studied are the stronger the urge "to be simple-minded" would become.(n16)

If international politics is a recalcitrant realm for the theorist, then its special difficulties lie elsewhere than in the first three of Aron’s points. Are they perhaps found in the last three? As the fourth of Aron’s impediments to theory, I have listed the absence of "accounting identities" or, as others have put it, the lack of a unit of measure and a medium of exchange in which goals can be valued and instruments comparatively priced. Political capability end political effect, whether or not conceived of simply in terms of power, cannot be expressed in units, such as dollars, that would have clear meaning and be applicable to different instruments and ends. Yet one finds in Adam Smith, for example, no numbers that are essential to his theory. Indeed, one finds hardly any numbers at all, and thus no "accounting identities." That supply equals demand or that investment equals savings are general propositions or purported laws that theory may explain. Stating the laws does not depend on counting, weighing, or measuring anything. As Frank Knight well and rightly wrote:

Pure theory, in economics as in any field, is abstract; it deals with forms only, in complete abstraction from content. On the individual side, economic theory takes men with (a) any wants whatever, (b) any resources whatever, and (c) any system of technology whatever, and develops principles of economic behaviour. The validity of its "laws" does not depend on the actual conditions or data, with respect to any of these three elementary phases of economic action.(n17)

In politics, not everything can be counted or measured, but some things can be. That may be helpful in the application of theories but has nothing to do with their construction.

The fifth and sixth difficulties discovered by Aron seem to tell us something substantive about polities rasher then about its amenability to theory and its status as science. In classical economic theory, no mechanism-that is, no agent or institution-restores a lost equilibrium. Classical and neoclassical economists were microtheorists-market and exchange relations emerge from the exercise of individual choice. The economy is produced by the interaction of persons and firms; it cannot be said to have goals or purposes of its own.(n18) Governments may, of course, act to restore a lost equilibrium. So may powerful persons or firms within the economy. But at this point we leave the realm of theory and enter the realm of practice-or "sociology" as Aron uses the term. "Any concrete study of international relations is sociological," he avers.(n19) The characteristic attaches to concrete studies and not simply to the study of international politics.

Aron identifies science with the ability to predict and control.(n20) Yet theories of evolution predict nothing in particular. Astronomers do predict (although without controlling), but what entices astronomy to be called a science is not the ability to predict but the ability to specify causes, to state the theories and laws by which the predictions are made. Economic theory is impressive even when economists show themselves to be unreliable in prediction and prescription alike. Since theory abstracts from much of the complication of the world in an effort to explain it, the application of theory in any realm is a perplexing and uncertain matter.

Aron’s first three problems can be solved, although in the realm of theory all solutions are tentative. Aron’s last three difficulties are not impediments to the construction of theory but rather to its application and testing.

International Politics: Within the Theoretical Pale
The new realism, in contrast to the old, begins by proposing a solution to the problem of distinguishing factors internal to international political systems from those that are external. Theory isolates one realm from others in order to deal with it intellectually. By depicting an international-political system as a whole, with structural and unit levels at once distinct and connected, neorealism establishes the autonomy of international politics and,thus makes a theory about it possible.(n21) Neorealism develops the concept of a system’s structure which at once bounds the domain that students of international politics deal with and enables them to see how the structure of the system, and variations in it, affect the interacting units and the outcomes they produce. International structure emerges from the interaction of states and then constrains them from taking certain actions while propelling them toward others.

The concept of structure is based on the fact that units differently juxtaposed and combined behave differently and in interacting produce different outcomes. international structures are defined, first, by the ordering principle of the system, in our case anarchy, and second, by the distribution of capabilities across units. In an anarchic realm, structures are defined in terms of their major units. international structures vary with significant changes in the number of great powers. Great powers are marked off from others by the combined capabilities (or power) they command. When their number changes consequentially, the calculations and behaviors of states, and the outcomes their interactions produce, vary.

The idea that international politics can be thought of as a system with a precisely defined structure is neorealism’s fundamental departure from traditional realism. The spareness of the definition of international structure has attracted criticism. Robert Keohane asserts that neorealist theory "can be modified progressively to attain closer correspondence with reality."(n22) In the most sensitive and insightful essay on neorealism that I have read, Barry Buzan asks whether the logic of neorealism completely captures "the main features of the international political system." He answers this way:

"The criticisms of Ruggie, Keohane, and others suggest that it does not, because their concerns with factors such as dynamic density, information richness, communication facilities, and such like do not obviously fit into Waltz’s ostensibly ’systemic’ theory."(n23)

One wonders whether such factors as these can be seen as concepts that might become elements of a theory? "Dynamic density" would seem to be the most promising candidate. Yet dynamic density is not a part of a theory about one type of society or another. Rather it is a condition that develops in greater or lesser degree within and across societies. If the volume of transactions grows suffficiently, it will disrupt a simple society and transform it into a complex one. Dynamic density is not part of a theory of any society. Rather it is a social force developing in society that under certain circumstances may first disrupt and then transform it.(n24) The "such likes" mentioned by Buzan would not fit into any theory. Can one imagine how demographic trends, information richness and international institutions could be thrown into a theory? No theory can contain the "such likes," but if a theory is any good, it helps us to understand and explain them, to estimate their significance and to gauge their effects. Moreover, any theory leaves some things unexplained, and no theory enables one to move directly and easily from theory to application. Theories, one must add, are not useful merely because they may help one to understand, explain, and sometimes predict the trend of events. Equally important, they help one to understand how a given system works.

To achieve "closeness of fit" would negate theory. A theory cannot fit the facts or correspond with the events it seeks to explain. The ultimate closeness of fit would be achieved by writing a finely detailed description of the world that interests us. Nevertheless, neorealism continues to be criticized for its omissions. A theory can be written only by leaving out most matters that are of practical interest. To believe that listing the omissions of a theory constitutes a valid criticism is to misconstrue the theoretical enterprise.

The question of omissions arises because I limit the second term that defines structure to the distribution of power across nations. Now and then critics point out that logically many factors other than power, such as governmental form or national ideology, can be cast in distributional teens. Obviously so, but logic alone does not write theories. The question is not what does logic permit, but what does this theory require? Considerations of power dominate considerations of ideology. In a structural theory, states are differently placed by their power and differences in placement help to explain both their behavior and their fates. In any political system, the distribution of the unit’s capabilities is a key to explanation. The distribution of power is of special explanatory importance in self-help political systems because the units of the system are not formally differentiated with distinct functions specified as are the parts of hierarchic orders.

Barry Buzan raises questions about the adequacy "of defining structure within the relatively narrow sectoral terms of politics."(n25) It may be that a better theory could be devised by differently drawing the borders of the domain to which it will apply, by adding something to the theory, by subtracting something from it, or by altering assumptions and rearranging the relations among a theory’s concepts. But doing any or all of these things requires operations entirely different from the mere listing of omissions. Theory, after all, is mostly omissions. What is omitted cannot be added without thoroughly reworking the theory and turning it into a different one. Should one broaden the perspective of international-political theory to include economics? An international political-economic theory would presumably be twice as good as a theory of international politics alone. To fashion such a theory, one would have to show how the international political-economic domain can be marked off from others. One would first have to define its structures and then develop a theory to explain actions and outcomes within it. A political-economic theory would represent a long step toward a general theory of international relations, but no one has shown how to take it.

Those who want to disaggregate power as defined in neorealist theory are either calling for a new theory, while failing to provide one, or are pointing to some of the knotty problems that arise in the testing and application of theory. In the latter case, they, like Aron, confuse difficulties infesting and applying theory with the problem of constructing one.(n26) Critics of neorealist theory fail to understand that a theory is not a statement about everything that is important in international-political life, but rather a necessarily slender explanatory construct. Adding elements of practical importance would carry us back from a neorealist theory to a realist approach. The rich variety and wondrous complexity of international life would be reclaimed at the price of extinguishing theory.

Neorealism breaks with realism in four major ways. The first and most important one I have examined at some length. The remaining three I shall treat more briefly. They follow from, and are made possible by, the first one. Neorealism departs from traditional realism in the following additional ways: Neorealism produces a shift in causal relations, offers a different interpretation of power, and treats the unit level differently.

Theory and Reality
Causal Directions
Constructing theories according to different suppositions alters the appearance of whole fields of inquiry. A new theory draws attention to new objects of inquiry, interchanges causes and effects, and addresses different worlds. When John Hobson cast economics in macrotheoretical terms, he baffled his fellow economists. The London Extension Board would not allow him to offer courses on political economy because an economics professor who had read Hobson’s book thought it "equivalent in rationality to an attempt to prove the flatness of the earth."(n27) Hobson’s figure was apt. Microtheory, the economic orthodoxy of the day, portrayed a world different from the one that Hobson’s macrotheory revealed.

Similarly, the neorealist’s world looks different from the one that earlier realists had portrayed. For realists, the world addressed is one of interacting states. For neorealists, interacting states can be adequately studied only by distinguishing between structural and unit-level causes and effects. Structure becomes a new object of inquiry, as well as an occasion for argument. In the light of neorealist theory, means and ends are differently viewed, as are causes and effects. Realists think of causes running in one direction, from interacting states to the outcomes their acts and interactions produce. This is clearly seen in Morgenthau’s "Six Principles of Political Realism," which form the substance of a chapter headed "A Realist Theory of International Politics."(n28) Strikingly, one finds much said about foreign policy and little about international politics. The principles develop as Morgenthau searches for his well-known "rational outline, a map that suggests to us the possible meanings of foreign policy."(n29) The principles are about human nature, about interest and power, and about questions of morality. Political realism offers the perspective in which the actions of statesmen are to be understood and judged. Morgenthau’s work was in harmony with the developing political science of his day, although at the time this was not seen. Methodological presuppositions shape the conduct of inquiry. The political-science paradigm was becoming deeply entrenched. Its logic is preeminently behavioral. The established paradigm of any field indicates what facts to scrutinize and how they are interconnected. Behavioral logic explains political outcomes through examining the constituent parts of political systems. When Aron and other traditionalists insist that theorists’ categories be consonant with actors’ motives and perceptions, they are affirming the preeminently behavioral logic that their inquiries follow.(n30) The characteristics and the interactions of behavioral units are taken to be the direct causes of political events, whether in the study of national or of international politics. Aron, Morgenthau and other realists tried to understand and explain international outcomes by examining the actions and interactions of the units, the states that populate the international arena and those who guide their policies. Realism’s approach is primarily inductive. Neorealism is more heavily deductive.

Like classical economists before them, realists were unable to account for a major anomaly. Classical theory held that disequilibria would be righted by the working of market forces without need for governmental intervention. Hobson’s, and later in fuller form John Maynard Keynes’s, macroeconomic theory explained why in the natural course of events recovery from depressions was such a long time coming.(n31) A similarly big anomaly in realist theory is seen in the attempt to explain alternations of war and peace. Like most students of international politics, realists infer outcomes from the salient attributes of the actors producing them. Governmental forms, economic systems, social institutions, political ideologies--hese are but a few examples of where the causes of war and peace have been found. Yet, although causes are specifically assigned, we know that states with every imaginable variation of economic institution, social custom, and political ideology have fought wars. If an indicated condition seems to have caused a given war, one must wonder what accounts for the repetition of wars even as their causes vary. Variations in the quality of the units are not linked directly to the outcomes their behaviors produce, nor are variations in patterns of interaction. Many, for example, have claimed that World War I was caused by the interaction of two opposed and closely balanced coalitions. But then many have claimed that World War II was caused by the failure of some states to right an imbalance of power by combining to counter an existing alliance. Over the centuries, the texture of international life has remained impressively, or depressingly, uniform even while profound changes were taking place in the composition of states which, according to realists, account for national behavior and international outcomes. Realists cannot explain the disjunction between supposed causes and observed effects. Neorealists can.

Neorealism contends that international politics can be understood only if the effects of structure are added to traditional realism’s unit-level explanations. More generally, neorealism reconceives the causal link between interacting units and international outcomes. Neorealist theory shows that causes run not in one direction, from interacting units to outcomes produced, but rather in two directions. One must believe that some causes of international outcomes are located at the level of the interacting units. Since variations in unit-level causes do not correspond to variations in observed outcomes, one has to believe that some causes are located at the structural level of international politics as well. Realists cannot handle causation at a level above states because they fail to conceive of structure as a force that shapes and shoves the units. Causes at the level of units interact with those at the level of the structure and because they do so explanation at the level of units alone is bound to mislead. If one’s theory allows for the handling of both unit-level and structure-level causes, then it can cope with both the changes and the continuities that occur in a system.

Power as Means and End
For many realists, the desire for power is rooted in the nature of man. Morgenthau recognized that given competition for scarce goods with no one to serve as arbiter, a struggle for power will ensue among the competitors, and that consequently the struggle for power can be explained without reference to the evil born in men. The struggle for power arises because people want things and not necessarily because of the evil in their desires. This he labels one of the two roots of conflict, but even while discussing it he pulls toward the "other root of conflict and concomitant evil"--the animus dominandi, the desire for power. He often considers man’s drive for power as a datum more basic than the chance conditions under which struggles for power occur.(n32)

The reasoning is faithful to Hobbes for whom the three causes of quarrels were competition, diffidence (i.e., distrust), and glory. Competition leads to fighting for gain, diffidence to fighting to keep what has been gained, glory to fighting for reputation. Because some hunger for power, it behooves others to cultivate their appetites.(n33) For Morgenthau, as for Hobbes, even if one has plenty of power and is secure in its possession, more power is nevertheless wanted. As Morgenthau put it:

Since the desire to attain a maximum of power is universal, all nations must always be afraid that their own miscalculations and the power increases of other nations might add up to an inferiority for themselves which they must at all costs try to avoid.(n34)

Both Hobbes and Morgenthau see that conflict is in part situationally explained, but both believe that even were it not so, pride, lust, and the quest for glory would cause the war of all against all to continue indefinitely. Ultimately, conflict and war are rooted in human nature.

The preoccupation with the qualities of man is understandable in view of the purposes Hobbes and Morgenthau entertain. Both are interested in understanding the state. Hobbes seeks a logical explanation of its emergence; Morgenthau seeks to explain how it behaves internationally. Morgenthau thought of the "rational" statesman as striving ever to accumulate more and more power. Power is seen as an end in itself. Nations at times may act aside from considerations of power. When they do, Morgenthau insists, their actions are not "of a political nature."(n35) The claim that "the desire to attain a maximum of power is universal" among nations is one of Morgenthau’s "objective laws that have their roots in human nature."(n36) Yet much of the behavior of nations contradicts it. Morgenthau does not explain why other desires fail to moderate or outweigh the fear states may have about miscalculation of their relative power. His opinions about power are congenial to realism. They are easily slipped into because the effort to explain behavior and outcomes by the characteristics of units leads realists to assign to them attributes that seem to accord with behavior and outcomes observed. Unable to conceive of international politics as a self-sustaining system, realists concentrate on the behavior and outcomes that seem to follow from the characteristics they have attributed to men and states. Neorealists, rather than viewing power as an end in itself, see power as a possibly useful means, with states running risks if they have either too little or too much of it. Weakness may invite an attack that greater strength would dissuade an adversary from launching. Excessive strength may prompt other states to increase their arms and pool their efforts. Power is a possibly useful means, and sensible statesmen try to have an appropriate amount of it. In crucial situations, the ultimate concern of states is not for power but for security. This is an important revision of realist theory.

A still more important one is neorealism’s use of the concept of power as a defining characteristic of structure. Power in neorealist theory is simply the combined capability of a state. Its distribution across states, and changes in that distribution, help to define structures and changes in them as explained above. Some complaints have been made about the absence of efforts on the part of neorealists to devise objective measures of power. Whatever the difficulties of measurement may be, they are not theoretical difficulties but practical ones encountered when moving from theory to its practical application.

Interacting Units
For realists, anarchy is a general condition rather than a distinct structure. Anarchy sets the problem that states have to cope with. Once this is understood, the emphasis of realists shifts to the interacting units. States are unlike one another in form of government, character of rulers, types of ideology, and in many other ways. For both realists and neorealists, differently constituted states behave differently and produce different outcomes. For neorealists, however, states are made functionally similar by the constraints of structure, with the principal differences among them defined according to capabilities. Forneorealists, moreover, structure mediates the outcomes that states produce. As internal and external circumstances change, structures and states may bear more or less causal weight. The question of the relative importance of different levels cannot be abstractly or definitively answered. Ambiguity cannot be resolved since structures affect units even as units affect structures. Some have thought that this is a defect of neorealist theory. It is so, however, only if factors at the unit level or at the structural level determine, rather than merely affect, outcomes. Theories cannot remove the uncertainty of politics, but only help us to comprehend it.

Neorealists concentrate their attention on the central, previously unanswered question in the study of international politics: How can the structure of an international-political system be distinguished from its interacting parts? Once that question is answered, attention shifts to the effects of structure on interacting units. Theorists concerned with structural explanations need not ask how variations in units affect outcomes, even though outcomes find their causes at both structural and unit levels. Neorealists see states as like units; each state "is like all other states in being an autonomous political unit." Autonomy is the unit-level counterpart of anarchy at the structural level.(n37) A theory of international politics can leave aside variation in the composition of states and in the resources and technology they command because the logic of anarchy does not vary with its content. Realists concentrate on the heterogeneity of states because they believe that differences of behavior and outcomes proceed directly from differences in the composition of units. Noticing that the proposition is faulty, neorealists offer a theory that explains how structures affect behavior and outcomes.

The logic of anarchy obtains whether the system is composed of tribes, nations, oligopolistic firms, or street gangs. Yet systems populated by units of different sorts in some ways perform differently, even though they share the same organizing principle. More needs to be said about the status and role of units in neorealist theory. More also needs to be said about changes in the background conditions against which states operate. Changes in the industrial and military technologies available to states, for example, may change the character of systems but do not change the theory by which their operation is explained. These are subjects for another essay. Here I have been concerned not to deny the many connections between the old and the new realism but to emphasize the most important theoretical changes that neorealism has wrought. I have been all the more concerned to do this since the influence of realist and behavioral logic lingers in the study of international politics, as in political science generally.

(n1.) I should like to thank David Schleicher for his help on this paper.

(n2.) William T.R. Fox, co-author and ea., Theoretical Aspects of international Relations (Notre Dame, IN: University of Notre Dame Press, 1959).

(n3.) Josiah Child, A New Discourse of Trade, 4th ed. (London: J. Hodges, 1740). See also William Letwin, Sir Josiah Child, Merchant Economist (Cambridge, MA: Harvard University Press, 1959).

(n4.) Joseph Schumpeter, Economic Doctrine and Method: An Historical Sketch, R. Aris, trans. (New York: Oxford University Press 1967) p.24.

(n5.) Ibid, p.30.

(n6.) Francois Quesnay was the foremost Physiocrat. His Tableau Oeconomique was published in 1758.

(n7.) Schumpeter, op. cit., pp.42-44, 46.

(n8.) Raymond Aron, "What is a Theory of International Relations?" Journal of International Affairs 21, no. 2 (1967) pp.185-206.

(n9.) Hans J. Morgenthau, Politics Among Nations, 5th ed. (New York: Alfred A. Knopf, 1972) p.7.

(n10.) Ibid., p.3.

(n11.) Morgenthau, Truth and Power (New York: Praeger, 1970) pp.253-258.

(n12.) Morgenthau, "International Relations: Quantitative and Qualitative Approaches," in Norman Palmer, ed., A Design for International Relations Research: Scope, Theory, Methods, and Relevance (Philadelphia: American Academy of Political and Social Science, 1970)p.78.

(n13.) Morgenthau (1972), op. cit., p. 12.

(n14.) Ludwig Boltzman, "Theories as Representations," excerpt, Rudolph Weingartner, trans., in Arthur Danto and Sidney Morgenbesser, eds., Philosophy of Science (Cleveland, OH: World, 1960).

(n15.) Aron, op. cit., p.198.

(n16.) "To be simple-minded" is Anatol Rapoport’s first rule for the construction of mathematical models. See his "Lewis F. Richardson’s Mathematical Theory of War," Journal of Conflict Resolution 1, no. 3 (1957) pp.275-276.

(n17.) Frank Hyneman Knight, The Ethics of Competition and Other Essays (London: George Allen & Unwin, 1936) p.281.

(n18.) See also James M. Buchanan, "An Individualistic Theory of Political Process," in David Easton, ea., Varieties of Political Theory (Englewood Cliffs, NJ: Prentice-Hall, 1966) pp.25-26.

(n19.) Aron, op.cit., p.198.

(n20.) Ibid., p. 201. See also Morgenthau (1970), op. cit., p.253.

(n21.) Neorealism is sometimes referred to as structural realism. throughout this essay I refer to my own formulation of neorealist theory. See esp. chs. 5-6 of Theory of International Politics (Reading, MA. Addison-Wesley, 1979).

(n22.) Robert 0. Keohane, "Theory of World Politics: Structural Realism and Beyond" in Keohane, ea., Neorealism and Its Critics (New York: Columbia University Press, 1986) p.191.

(n23.) Barry Buzan, "Systems, Structures and Units: Reconstructing Waltz’s Theory of international Politics," unpublished paper (April 1988) p.35.

(n24.) John G. Ruggie, "Continuity and Transformation in the World Polity," in Keohane, ed., op. cit., pp.148-152; Waltz, "A Response to my Critics," pp.323-326. Waltz (1979), op. cit., pp.126-128.

(n25.) Buzan, op. cit., p.11.

(n26.) See, for example., Joseph S. Nye, Jr., "Neorealism and Neoliberalism," in World Politics 40, no. 2, (January 1988) pp.241-245; Keohane, op. cit., pp. 184-200: Buzan, op. cit. pp.28-34.

(n27.) John Maynard Keynes, The General Theory of Employment, Interest, and Money (London: Macmillan, 1951) pp.365-6.

(n28.) Morgenthau (1972), op. cit., pp.4-14.

(n29.) Ibid.,p.5.

(n30.) See Waltz (1979), op. cit., pp. 44, 47, 62.

(n31.) In his General Theory, Keynes gives Hobson full credit for setting forth the basic concepts of macroeconomic theory.

(n32.) Morgenthau, Scientific Man vs. Power Politics (Chicago: University of Chicago Press, 1946) p. 192.

(n33.) Thomas Hobbes, Leviathan.

(n34.) Morgenthau (1972), op. cit., p.208.

(n35.) Ibid., p. 27.

(n36.) Ibid.

(n37) On page 95 of Theory of International Politics, I slipped into using "sovereignty" for "autonomy." Sovereignty, Ruggie points out, is particular to the modem state. See his "Continuity and Transformation," in Keohane, ea., op. cit., pp.142-148