1

Introduction

Many in the West seem to believe that “perpetual peace” among the great powers is finally at hand. The end of the Cold War, so the argument goes, marked a sea change in how great powers interact with one another. We have entered a world in which there is little chance that the major powers will engage each other in security competition, much less war, which has become an obsolescent enterprise. In the words of one famous author, the end of the Cold War has brought us to the “the end of history.”¹

This perspective suggests that great powers no longer view each other as potential military rivals, but instead as members of a family of nations, members of what is sometimes called the “international community.” The prospects for cooperation are abundant in this promising new world, a world which is likely to bring increased prosperity and peace to all the great powers. Even a few adherents of realism, a school of thought that has historically held pessimistic views about the prospects for peace among the great powers, appear to have bought into the reigning optimism, as reflected in an article from the mid-1990s titled “Realists as Optimists.”²

Alas, the claim that security competition and war between the great powers have been purged from the international system is wrong. Indeed, there is much evidence that the promise of everlasting peace among the great powers was stillborn. Consider, for example, that even though the Soviet threat has disappeared, the United States still maintains about one hundred thousand troops in Europe and roughly the same number in Northeast Asia. It does so because it recognizes that dangerous rivalries would probably emerge among the major powers in these regions if U.S. troops were withdrawn. Moreover, almost every European state, including the United Kingdom and France, still harbors deep-seated, albeit muted, fears that a Germany unchecked by American power might behave aggressively; fear of Japan in Northeast Asia is probably even more profound, and it is certainly more frequently expressed. Finally, the possibility of a clash between China and the United States over Taiwan is hardly remote. This is not to say that such a war is likely, but the possibility reminds us that the threat of great-power war has not disappeared.

The sad fact is that international politics has always been a ruthless and dangerous business, and it is likely to remain that way. Although the intensity of their competition waxes and wanes, great powers fear each other and always compete with each other for power. The overriding goal of each state is to maximize its share of world power, which means gaining power at the expense of other states. But great powers do not merely strive to be the strongest of all the great powers, although that is a welcome outcome. Their ultimate aim is to be the hegemon—that is, the only great power in the system.

There are no status quo powers in the international system, save for the occasional hegemon that wants to maintain its dominating position over potential rivals. Great powers are rarely content with the current distribution of power; on the contrary, they face a constant incentive to change it in their favor. They almost always have revisionist intentions, and they will use force to alter the balance of power if they think it can be done at a reasonable price.³ At times, the costs and risks of trying to shift the balance of power are too great, forcing great powers to wait for more favorable circumstances. But the desire for more power does not go away, unless a state achieves the ultimate goal of hegemony. Since no state is likely to achieve global hegemony, however, the world is condemned to perpetual great-power competition.

This unrelenting pursuit of power means that great powers are inclined to look for opportunities to alter the distribution of world power in their favor. They will seize these opportunities if they have the necessary capability. Simply put, great powers are primed for offense. But not only does a great power seek to gain power at the expense of other states, it also tries to thwart rivals bent on gaining power at its expense. Thus, a great power will defend the balance of power when looming change favors another state, and it will try to undermine the balance when the direction of change is in its own favor.

Why do great powers behave this way? My answer is that the structure of the international system forces states which seek only to be secure nonetheless to act aggressively toward each other. Three features of the international system combine to cause states to fear one another: 1) the absence of a central authority that sits above states and can protect them from each other, 2) the fact that states always have some offensive military capability, and 3) the fact that states can never be certain about other states’ intentions. Given this fear—which can never be wholly eliminated—states recognize that the more powerful they are relative to their rivals, the better their chances of survival. Indeed, the best guarantee of survival is to be a hegemon, because no other state can seriously threaten such a mighty power.

This situation, which no one consciously designed or intended, is genuinely tragic. Great powers that have no reason to fight each other—that are merely concerned with their own survival—nevertheless have little choice but to pursue power and to seek to dominate the other states in the system. This dilemma is captured in brutally frank comments that Prussian statesman Otto von Bismarck made during the early 1860s, when it appeared that Poland, which was not an independent state at the time, might regain its sovereignty. “Restoring the Kingdom of Poland in any shape or form is tantamount to creating an ally for any enemy that chooses to attack us,” he believed, and therefore he advocated that Prussia should “smash those Poles till, losing all hope, they lie down and die; I have every sympathy for their situation, but if we wish to survive we have no choice but to wipe them out.”⁴

Although it is depressing to realize that great powers might think and act this way, it behooves us to see the world as it is, not as we would like it to be. For example, one of the key foreign policy issues facing the United States is the question of how China will behave if its rapid economic growth continues and effectively turns China into a giant Hong Kong. Many Americans believe that if China is democratic and enmeshed in the global capitalist system, it will not act aggressively; instead it will be content with the status quo in Northeast Asia. According to this logic, the United States should engage China in order to promote the latter’s integration into the world economy, a policy that also seeks to encourage China’s transition to democracy. If engagement succeeds, the United States can work with a wealthy and democratic China to promote peace around the globe.

Unfortunately, a policy of engagement is doomed to fail. If China becomes an economic powerhouse it will almost certainly translate its economic might into military might and make a run at dominating Northeast Asia. Whether China is democratic and deeply enmeshed in the global economy or autocratic and autarkic will have little effect on its behavior, because democracies care about security as much as non-democracies do, and hegemony is the best way for any state to guarantee its own survival. Of course, neither its neighbors nor the United States would stand idly by while China gained increasing increments of power. Instead, they would seek to contain China, probably by trying to form a balancing coalition. The result would be an intense security competition between China and its rivals, with the ever-present danger of great-power war hanging over them. In short, China and the United States are destined to be adversaries as China’s power grows.

OFFENSIVE REALISM

This book offers a realist theory of international politics that challenges the prevailing optimism about relations among the great powers. That enterprise involves three particular tasks.

I begin by laying out the key components of the theory, which I call “offensive realism.” I make a number of arguments about how great powers behave toward each other, emphasizing that they look for opportunities to gain power at each others’ expense. Moreover, I identify the conditions that make conflict more or less likely. For example, I argue that multipolar systems are more war-prone than are bipolar systems, and that multipolar systems that contain especially powerful states—potential hegemons—are the most dangerous systems of all. But I do not just assert these various claims; I also attempt to provide compelling explanations for the behaviors and the outcomes that lie at the heart of the theory. In other words, I lay out the causal logic, or reasoning, which underpins each of my claims.

The theory focuses on the great powers because these states have the largest impact on what happens in international politics.⁵ The fortunes of all states—great powers and smaller powers alike—are determined primarily by the decisions and actions of those with the greatest capability. For example, politics in almost every region of the world were deeply influenced by the competition between the Soviet Union and the United States between 1945 and 1990. The two world wars that preceded the Cold War had a similar effect on regional politics around the world. Each of these conflicts was a great-power rivalry, and each cast a long shadow over every part of the globe.

Great powers are determined largely on the basis of their relative military capability. To qualify as a great power, a state must have sufficient military assets to put up a serious fight in an all-out conventional war against the most powerful state in the world.⁶ The candidate need not have the capability to defeat the leading state, but it must have some reasonable prospect of turning the conflict into a war of attrition that leaves the dominant state seriously weakened, even if that dominant state ultimately wins the war. In the nuclear age great powers must have a nuclear deterrent that can survive a nuclear strike against it, as well as formidable conventional forces. In the unlikely event that one state gained nuclear superiority over all of its rivals, it would be so powerful that it would be the only great power in the system. The balance of conventional forces would be largely irrelevant if a nuclear hegemon were to emerge.

My second task in this book is to show that the theory tells us a lot about the history of international politics. The ultimate test of any theory is how well it explains events in the real world, so I go to considerable lengths to test my arguments against the historical record. Specifically, the focus is on great-power relations from the start of the French Revolutionary and Napoleonic Wars in 1792 until the end of the twentieth century.⁷ Much attention is paid to the European great powers because they dominated world politics for most of the past two hundred years. Indeed, until Japan and the United States achieved great-power status in 1895 and 1898, respectively, Europe was home to all of the world’s great powers. Nevertheless, the book also includes substantial discussion of the politics of Northeast Asia, especially regarding imperial Japan between 1895 and 1945 and China in the 1990s. The United States also figures prominently in my efforts to test offensive realism against past events.

Some of the important historical puzzles that I attempt to shed light on include the following:

1) What accounts for the three longest and bloodiest wars in modern history—the French Revolutionary and Napoleonic Wars (1792–1815), World War I (1914–18), and World War II (1939–45)—conflicts that involved all of the major powers in the system?

2) What accounts for the long periods of relative peace in Europe between 1816 and 1852, 1871 and 1913, and especially 1945 and 1990, during the Cold War?

3) Why did the United Kingdom, which was by far the wealthiest state in the world during the mid-nineteenth century, not build a powerful military and try to dominate Europe? In other words, why did it behave differently from Napoleonic France, Wilhelmine Germany, Nazi Germany, and the Soviet Union, all of which translated their economic might into military might and strove for European hegemony?

4) Why was Bismarckian Germany (1862–90) especially aggressive between 1862 and 1870, fighting two wars with other great powers and one war with a minor power, but hardly aggressive at all from 1871 until 1890, when it fought no wars and generally sought to maintain the European status quo?

5) Why did the United Kingdom, France, and Russia form a balancing coalition against Wilhelmine Germany before World War I, but fail to organize an effective alliance to contain Nazi Germany?

6) Why did Japan and the states of Western Europe join forces with the United States against the Soviet Union in the early years of the Cold War, even though the United States emerged from World War II with the most powerful economy in the world and a nuclear monopoly?

7) What explains the commitment of American troops to Europe and Northeast Asia during the twentieth century? For example, why did the United States wait until April 1917 to join World War I, rather than enter the war when it broke out in August 1914? For that matter, why did the United States not send troops to Europe before 1914 to prevent the outbreak of war? Similarly, why did the United States not balance against Nazi Germany in the 1930s or send troops to Europe before September 1939 to prevent the outbreak of World War II?

8) Why did the United States and the Soviet Union continue building up their nuclear arsenals after each had acquired a secure second-strike capability against the other? A world in which both sides have an “assured destruction” capability is generally considered to be stable and its nuclear balance difficult to overturn, yet both superpowers spent billions of dollars and rubles trying to gain a first-strike advantage.

Third, I use the theory to make predictions about great-power politics in the twenty-first century. This effort may strike some readers as foolhardy, because the study of international relations, like the other social sciences, rests on a shakier theoretical foundation than that of the natural sciences. Moreover, political phenomena are highly complex; hence, precise political predictions are impossible without theoretical tools that are superior to those we now possess. As a result, all political forecasting is bound to include some error. Those who venture to predict, as I do here, should therefore proceed with humility, take care not to exhibit unwarranted confidence, and admit that hindsight is likely to reveal surprises and mistakes.

Despite these hazards, social scientists should nevertheless use their theories to make predictions about the future. Making predictions helps inform policy discourse, because it helps make sense of events unfolding in the world around us. And by clarifying points of disagreement, making explicit forecasts helps those with contradictory views to frame their own ideas more clearly. Furthermore, trying to anticipate new events is a good way to test social science theories, because theorists do not have the benefit of hindsight and therefore cannot adjust their claims to fit the evidence (because it is not yet available). In short, the world can be used as a laboratory to decide which theories best explain international politics. In that spirit, I employ offensive realism to peer into the future, mindful of both the benefits and the hazards of trying to predict events.

The Virtues and Limits of Theory

It should be apparent that this book is self-consciously theoretical. But outside the walls of academia, especially in the policy world, theory has a bad name. Social science theories are often portrayed as the idle speculations of head-in-the-clouds academics that have little relevance to what goes on in the “real world.” For example, Paul Nitze, a prominent American foreign-policy maker during the Cold War, wrote, “Most of what has been written and taught under the heading of ‘political science’ by Americans since World War II has been…of limited value, if not counterproductive, as a guide to the actual conduct of policy.”⁸ In this view, theory should fall almost exclusively within the purview of academics, whereas policymakers should rely on common sense, intuition, and practical experience to carry out their duties.

This view is wrongheaded. In fact, none of us could understand the world we live in or make intelligent decisions without theories. Indeed, all students and practitioners of international politics rely on theories to comprehend their surroundings. Some are aware of it and some are not, some admit it and some do not; but there is no escaping the fact that we could not make sense of the complex world around us without simplifying theories. The Clinton administration’s foreign policy rhetoric, for example, was heavily informed by the three main liberal theories of international relations: 1) the claim that prosperous and economically interdependent states are unlikely to fight each other, 2) the claim that democracies do not fight each other, and 3) the claim that international institutions enable states to avoid war and concentrate instead on building cooperative relationships.

Consider how Clinton and company justified expanding the membership of the North Atlantic Treaty Organization (NATO) in the mid-1990s. President Clinton maintained that one of the chief goals of expansion was “locking in democracy’s gains in Central Europe,” because “democracies resolve their differences peacefully.” He also argued that the United States should foster an “open trading system,” because “our security is tied to the stake other nations have in the prosperity of staying free and open and working with others, not working against them.”⁹ Strobe Talbott, Clinton’s Oxford classmate and deputy secretary of state, made the same claims for NATO enlargement: “With the end of the cold war, it has become possible to construct a Europe that is increasingly united by a shared commitment to open societies and open markets.” Moving the borders of NATO eastward, he maintained, would help “to solidify the national consensus for democratic and market reforms” that already existed in states like Hungary and Poland and thus enhance the prospects for peace in the region.¹⁰

In the same spirit, Secretary of State Madeleine Albright praised NATO’s founders by saying that “[t]heir basic achievement was to begin the construction of the…network of rule-based institutions and arrangements that keep the peace.” “But that achievement is not complete,” she warned, and “our challenge today is to finish the post-war construction project…[and] expand the area of the world in which American interests and values will thrive.”¹¹

These examples demonstrate that general theories about how the world works play an important role in how policymakers identify the ends they seek and the means they choose to achieve them. Yet that is not to say we should embrace any theory that is widely held, no matter how popular it may be, because there are bad as well as good theories. For example, some theories deal with trivial issues, while others are opaque and almost impossible to comprehend. Furthermore, some theories have contradictions in their underlying logic, while others have little explanatory power because the world simply does not work the way they predict. The trick is to distinguish between sound theories and defective ones.¹² My aim is to persuade readers that offensive realism is a rich theory which sheds considerable light on the workings of the international system.

As with all theories, however, there are limits to offensive realism’s explanatory power. A few cases contradict the main claims of the theory, cases that offensive realism should be able to explain but cannot. All theories face this problem, although the better the theory, the fewer the anomalies.

An example of a case that contradicts offensive realism involves Germany in 1905. At the time Germany was the most powerful state in Europe. Its main rivals on the continent were France and Russia, which some fifteen years earlier had formed an alliance to contain the Germans. The United Kingdom had a tiny army at the time because it was counting on France and Russia to keep Germany at bay. When Japan unexpectedly inflicted a devastating defeat on Russia between 1904 and 1905, which temporarily knocked Russia out of the European balance of power, France was left standing virtually alone against mighty Germany. Here was an excellent opportunity for Germany to crush France and take a giant step toward achieving hegemony in Europe. It surely made more sense for Germany to go to war in 1905 than in 1914. But Germany did not even seriously consider going to war in 1905, which contradicts what offensive realism would predict.

Theories encounter anomalies because they simplify reality by emphasizing certain factors while ignoring others. Offensive realism assumes that the international system strongly shapes the behavior of states. Structural factors such as anarchy and the distribution of power, I argue, are what matter most for explaining international politics. The theory pays little attention to individuals or domestic political considerations such as ideology. It tends to treat states like black boxes or billiard balls. For example, it does not matter for the theory whether Germany in 1905 was led by Bismarck, Kaiser Wilhelm, or Adolf Hitler, or whether Germany was democratic or autocratic. What matters for the theory is how much relative power Germany possessed at the time. These omitted factors, however, occasionally dominate a state’s decision-making process; under these circumstances, offensive realism is not going to perform as well. In short, there is a price to pay for simplifying reality.

Furthermore, offensive realism does not answer every question that arises in world politics, because there will be cases in which the theory is consistent with several possible outcomes. When this occurs, other theories have to be brought in to provide more precise explanations. Social scientists say that a theory is “indeterminate” in such cases, a situation that is not unusual with broad-gauged theories like offensive realism.

An example of offensive realism’s indeterminacy is that it cannot account for why the security competition between the superpowers during the Cold War was more intense between 1945 and 1963 than between 1963 and 1990.¹³ The theory also has little to say about whether NATO should have adopted an offensive or a defensive military strategy to deter the Warsaw Pact in central Europe.¹⁴ To answer these questions it is necessary to employ more fine-grained theories, such as deterrence theory. Nevertheless, those theories and the answers they spawn do not contradict offensive realism; they supplement it. In short, offensive realism is like a powerful flashlight in a dark room: even though it cannot illuminate every nook and cranny, most of the time it is an excellent tool for navigating through the darkness.

It should be apparent from this discussion that offensive realism is mainly a descriptive theory. It explains how great powers have behaved in the past and how they are likely to behave in the future. But it is also a prescriptive theory. States should behave according to the dictates of offensive realism, because it outlines the best way to survive in a dangerous world.

One might ask, if the theory describes how great powers act, why is it necessary to stipulate how they should act? The imposing constraints of the system should leave great powers with little choice but to act as the theory predicts. Although there is much truth in this description of great powers as prisoners trapped in an iron cage, the fact remains that they sometimes—although not often—act in contradiction to the theory. These are the anomalous cases discussed above. As we shall see, such foolish behavior invariably has negative consequences. In short, if they want to survive, great powers should always act like good offensive realists.

The Pursuit of Power

Enough said about theory. More needs to be said about the substance of my arguments, which means zeroing in on the core concept of “power.” For all realists, calculations about power lie at the heart of how states think about the world around them. Power is the currency of great-power politics, and states compete for it among themselves. What money is to economics, power is to international relations.

This book is organized around six questions dealing with power. First, why do great powers want power? What is the underlying logic that explains why states compete for it? Second, how much power do states want? How much power is enough? These two questions are of paramount importance because they deal with the most basic issues concerning great-power behavior. My answer to these foundational questions, as emphasized above, is that the structure of the international system encourages states to pursue hegemony.

Third, what is power? How is that pivotal concept defined and measured? With good indicators of power, it is possible to determine the power levels of individual states, which then allows us to describe the architecture of the system. Specifically, we can identify which states qualify as great powers. From there, it is easy to determine whether the system is hegemonic (directed by a single great power), bipolar (controlled by two great powers), or multipolar (dominated by three or more great powers). Furthermore, we will know the relative strengths of the major powers. We are especially interested in knowing whether power is distributed more or less evenly among them, or if there are large power asymmetries. In particular, does the system contain a potential hegemon—a great power that is considerably stronger than any of its rival great powers?

Defining power clearly also gives us a window into understanding state behavior. If states compete for power, we learn more about the nature of that competition if we understand more fully what power is, and therefore what states are competing for. In short, knowing more about the true nature of power should help illuminate how great powers compete among themselves.

Fourth, what strategies do states pursue to gain power, or to maintain it when another great power threatens to upset the balance of power? Blackmail and war are the main strategies that states employ to acquire power, and balancing and buck-passing are the principal strategies that great powers use to maintain the distribution of power when facing a dangerous rival. With balancing, the threatened state accepts the burden of deterring its adversary and commits substantial resources to achieving that goal. With buck-passing, the endangered great power tries to get another state to shoulder the burden of deterring or defeating the threatening state.

The final two questions focus on the key strategies that states employ to maximize their share of world power. The fifth is, what are the causes of war? Specifically, what power-related factors make it more or less likely that security competition will intensify and turn into open conflict? Sixth, when do threatened great powers balance against a dangerous adversary and when do they attempt to pass the buck to another threatened state?

I will attempt to provide clear and convincing answers to these questions. It should be emphasized, however, that there is no consensus among realists on the answers to any of them. Realism is a rich tradition with a long history, and disputes over fundamental issues have long been commonplace among realists. In the pages that follow, I do not consider alternative realist theories in much detail. I will make clear how offensive realism differs from its main realist rivals, and I will challenge these alternative perspectives on particular points, mainly to elucidate my own arguments. But no attempt will be made to systematically examine any other realist theory. Instead, the focus will be on laying out my theory of offensive realism and using it to explain the past and predict the future.

Of course, there are also many nonrealist theories of international politics. Three different liberal theories were mentioned earlier; there are other nonrealist theories, such as social constructivism and bureaucratic politics, to name just two. I will briefly analyze some of these theories when I look at great-power politics after the Cold War (Chapter 10), mainly because they underpin many of the claims that international politics has undergone a fundamental change since 1990. Because of space limitations, however, I make no attempt at a comprehensive assessment of these nonrealist theories. Again, the emphasis in this study will be on making the case for offensive realism.

Nevertheless, it makes good sense at this point to describe the theories that dominate thinking about international relations in both the academic and policy worlds, and to show how offensive realism compares with its main realist and nonrealist competitors.

LIBERALISM VS. REALISM

Liberalism and realism are the two bodies of theory which hold places of privilege on the theoretical menu of international relations. Most of the great intellectual battles among international relations scholars take place either across the divide between realism and liberalism, or within those paradigms.¹⁵ To illustrate this point, consider the three most influential realist works of the twentieth century:

1) E. H. Carr’s The Twenty Years’ Crisis, 1919–1939, which was published in the United Kingdom shortly after World War II started in Europe (1939) and is still widely read today.

2) Hans Morgenthau’s Politics among Nations, which was first published in the United States in the early days of the Cold War (1948) and dominated the field of international relations for at least the next two decades.

3) Kenneth Waltz’s Theory of International Politics, which has dominated the field since it first appeared during the latter part of the Cold War (1979).¹⁶

All three of these realist giants critique some aspect of liberalism in their writings. For example, both Carr and Waltz take issue with the liberal claim that economic interdependence enhances the prospects for peace.¹⁷ More generally, Carr and Morgenthau frequently criticize liberals for holding utopian views of politics which, if followed, would lead states to disaster. At the same time, these realists also disagree about a number of important issues. Waltz, for example, challenges Morgenthau’s claim that multipolar systems are more stable than bipolar systems.¹⁸ Furthermore, whereas Morgenthau argues that states strive to gain power because they have an innate desire for power, Waltz maintains that the structure of the international system forces states to pursue power to enhance their prospects for survival. These examples are just a small sample of the differences among realist thinkers.¹⁹

Let us now look more closely at liberalism and realism, focusing first on the core beliefs shared by the theories in each paradigm, and second on the differences among specific liberal and realist theories.

Liberalism

The liberal tradition has its roots in the Enlightenment, that period in eighteenth-century Europe when intellectuals and political leaders had a powerful sense that reason could be employed to make the world a better place.²⁰ Accordingly, liberals tend to be hopeful about the prospects of making the world safer and more peaceful. Most liberals believe that it is possible to substantially reduce the scourge of war and to increase international prosperity. For this reason, liberal theories are sometimes labelled “utopian” or “idealist.”

Liberalism’s optimistic view of international politics is based on three core beliefs, which are common to almost all of the theories in the paradigm. First, liberals consider states to be the main actors in international politics. Second, they emphasize that the internal characteristics of states vary considerably, and that these differences have profound effects on state behavior.²¹ Furthermore, liberal theorists often believe that some internal arrangements (e.g., democracy) are inherently preferable to others (e.g., dictatorship). For liberals, therefore, there are “good” and “bad” states in the international system. Good states pursue cooperative policies and hardly ever start wars on their own, whereas bad states cause conflicts with other states and are prone to use force to get their way.²² Thus, the key to peace is to populate the world with good states.

Third, liberals believe that calculations about power matter little for explaining the behavior of good states. Other kinds of political and economic calculations matter more, although the form of those calculations varies from theory to theory, as will become apparent below. Bad states might be motivated by the desire to gain power at the expense of other states, but that is only because they are misguided. In an ideal world, where there are only good states, power would be largely irrelevant.

Among the various theories found under the big tent of liberalism, the three main ones mentioned earlier are particularly influential. The first argues that high levels of economic interdependence among states make them unlikely to fight each other.²³ The taproot of stability, according to this theory, is the creation and maintenance of a liberal economic order that allows for free economic exchange among states. Such an order makes states more prosperous, thereby bolstering peace, because prosperous states are more economically satisfied and satisfied states are more peaceful. Many wars are waged to gain or preserve wealth, but states have much less motive to initiate war if they are already wealthy. Furthermore, wealthy states with interdependent economies stand to become less prosperous if they fight each other, since they are biting the hand that feeds them. Once states establish extensive economic ties, in short, they avoid war and can concentrate instead on accumulating wealth.

The second, democratic peace theory, claims that democracies do not go to war against other democracies.²⁴ Thus, a world containing only democratic states would be a world without war. The argument here is not that democracies are less warlike than non-democracies, but rather that democracies do not fight among themselves. There are a variety of explanations for the democratic peace, but little agreement as to which one is correct. Liberal thinkers do agree, however, that democratic peace theory offers a direct challenge to realism and provides a powerful recipe for peace.

Finally, some liberals maintain that international institutions enhance the prospects for cooperation among states and thus significantly reduce the likelihood of war.²⁵ Institutions are not independent political entities that sit above states and force them to behave in acceptable ways. Instead, institutions are sets of rules that stipulate the ways in which states should cooperate and compete with each other. They prescribe acceptable forms of state behavior and proscribe unacceptable kinds of behavior. These rules are not imposed on states by some leviathan, but are negotiated by states, which agree to abide by the rules they created because it is in their interest to do so. Liberals claim that these institutions or rules can fundamentally change state behavior. Institutions, so the argument goes, can discourage states from calculating self-interest on the basis of how their every move affects their relative power position, and thus they push states away from war and promote peace.

Realism

In contrast to liberals, realists are pessimists when it comes to international politics. Realists agree that creating a peaceful world would be desirable, but they see no easy way to escape the harsh world of security competition and war. Creating a peaceful world is surely an attractive idea, but it is not a practical one. “Realism,” as Carr notes, “tends to emphasize the irresistible strength of existing forces and the inevitable character of existing tendencies, and to insist that the highest wisdom lies in accepting, and adapting oneself to these forces and these tendencies.”²⁶

This gloomy view of international relations is based on three core beliefs. First, realists, like liberals, treat states as the principal actors in world politics. Realists focus mainly on great powers, however, because these states dominate and shape international politics and they also cause the deadliest wars. Second, realists believe that the behavior of great powers is influenced mainly by their external environment, not by their internal characteristics. The structure of the international system, which all states must deal with, largely shapes their foreign policies. Realists tend not to draw sharp distinctions between “good” and “bad” states, because all great powers act according to the same logic regardless of their culture, political system, or who runs the government.²⁷ It is therefore difficult to discriminate among states, save for differences in relative power. In essence, great powers are like billiard balls that vary only in size.²⁸

Third, realists hold that calculations about power dominate states’ thinking, and that states compete for power among themselves. That competition sometimes necessitates going to war, which is considered an acceptable instrument of statecraft. To quote Carl von Clausewitz, the nineteenth-century military strategist, war is a continuation of politics by other means.²⁹ Finally, a zero-sum quality characterizes that competition, sometimes making it intense and unforgiving. States may cooperate with each other on occasion, but at root they have conflicting interests.

Although there are many realist theories dealing with different aspects of power, two of them stand above the others: human nature realism, which is laid out in Morgenthau’s Politics among Nations, and defensive realism, which is presented mainly in Waltz’s Theory of International Politics. What sets these works apart from those of other realists and makes them both important and controversial is that they provide answers to the two foundational questions described above. Specifically, they explain why states pursue power—that is, they have a story to tell about the causes of security competition—and each offers an argument about how much power a state is likely to want.

Some other famous realist thinkers concentrate on making the case that great powers care deeply about power, but they do not attempt to explain why states compete for power or what level of power states deem satisfactory. In essence, they provide a general defense of the realist approach, but they do not offer their own theory of international politics. The works of Carr and American diplomat George Kennan fit this description. In his seminal realist tract, The Twenty Years’ Crisis, Carr criticizes liberalism at length and argues that states are motivated principally by power considerations. Nevertheless, he says little about why states care about power or how much power they want.³⁰ Bluntly put, there is no theory in his book. The same basic pattern obtains in Kennan’s well-known book American Diplomacy, 1900–1950.³¹ Morgenthau and Waltz, on the other hand, offer their own theories of international relations, which is why they have dominated the discourse about world politics for the past fifty years.

Human nature realism, which is sometimes called “classical realism,” dominated the study of international relations from the late 1940s, when Morgenthau’s writings began attracting a large audience, until the early 1970s.³² It is based on the simple assumption that states are led by human beings who have a “will to power” hardwired into them at birth.³³ That is, states have an insatiable appetite for power, or what Morgenthau calls “a limitless lust for power,” which means that they constantly look for opportunities to take the offensive and dominate other states.³⁴ All states come with an “animus dominandi,” so there is no basis for discriminating among more aggressive and less aggressive states, and there certainly should be no room in the theory for status quo states.³⁵ Human nature realists recognize that international anarchy—the absence of a governing authority over the great powers—causes states to worry about the balance of power. But that structural constraint is treated as a second-order cause of state behavior. The principal driving force in international politics is the will to power inherent in every state in the system, and it pushes each of them to strive for supremacy.

Defensive realism, which is frequently referred to as “structural realism,” came on the scene in the late 1970s with the appearance of Waltz’s Theory of International Politics.³⁶ Unlike Morgenthau, Waltz does not assume that great powers are inherently aggressive because they are infused with a will to power; instead he starts by assuming that states merely aim to survive. Above all else, they seek security. Nevertheless, he maintains that the structure of the international system forces great powers to pay careful attention to the balance of power. In particular, anarchy forces security-seeking states to compete with each other for power, because power is the best means to survival. Whereas human nature is the deep cause of security competition in Morgenthau’s theory, anarchy plays that role in Waltz’s theory.³⁷

Waltz does not emphasize, however, that the international system provides great powers with good reasons to act offensively to gain power. Instead, he appears to make the opposite case: that anarchy encourages states to behave defensively and to maintain rather than upset the balance of power. “The first concern of states,” he writes, is “to maintain their position in the system.”³⁸ There seems to be, as international relations theorist Randall Schweller notes, a “status quo bias” in Waltz’s theory.³⁹

Waltz recognizes that states have incentives to gain power at their rivals’ expense and that it makes good strategic sense to act on that motive when the time is right. But he does not develop that line of argument in any detail. On the contrary, he emphasizes that when great powers behave aggressively, the potential victims usually balance against the aggressor and thwart its efforts to gain power.⁴⁰ For Waltz, in short, balancing checkmates offense.⁴¹ Furthermore, he stresses that great powers must be careful not to acquire too much power, because “excessive strength” is likely to cause other states to join forces against them, thereby leaving them worse off than they would have been had they refrained from seeking additional increments of power.⁴²

Waltz’s views on the causes of war further reflect his theory’s status quo bias. There are no profound or deep causes of war in his theory. In particular, he does not suggest that there might be important benefits to be gained from war. In fact, he says little about the causes of war, other than to argue that wars are largely the result of uncertainty and miscalculation. In other words, if states knew better, they would not start wars.

Robert Jervis, Jack Snyder, and Stephen Van Evera buttress the defensive realists’ case by focusing attention on a structural concept known as the offense-defense balance.⁴³ They maintain that military power at any point in time can be categorized as favoring either offense or defense. If defense has a clear advantage over offense, and conquest is therefore difficult, great powers will have little incentive to use force to gain power and will concentrate instead on protecting what they have. When defense has the advantage, protecting what you have should be a relatively easy task. Alternatively, if offense is easier, states will be sorely tempted to try conquering each other, and there will be a lot of war in the system. Defensive realists argue, however, that the offense-defense balance is usually heavily tilted toward defense, thus making conquest extremely difficult.⁴⁴ In sum, efficient balancing coupled with the natural advantages of defense over offense should discourage great powers from pursuing aggressive strategies and instead make them “defensive positionalists.”⁴⁵

My theory of offensive realism is also a structural theory of international politics. As with defensive realism, my theory sees great powers as concerned mainly with figuring out how to survive in a world where there is no agency to protect them from each other; they quickly realize that power is the key to their survival. Offensive realism parts company with defensive realism over the question of how much power states want. For defensive realists, the international structure provides states with little incentive to seek additional increments of power; instead it pushes them to maintain the existing balance of power. Preserving power, rather than increasing it, is the main goal of states. Offensive realists, on the other hand, believe that status quo powers are rarely found in world politics, because the international system creates powerful incentives for states to look for opportunities to gain power at the expense of rivals, and to take advantage of those situations when the benefits outweigh the costs. A state’s ultimate goal is to be the hegemon in the system.⁴⁶

It should be apparent that both offensive realism and human nature realism portray great powers as relentlessly seeking power. The key difference between the two perspectives is that offensive realists reject Morgenthau’s claim that states are naturally endowed with Type A personalities. On the contrary, they believe that the international system forces great powers to maximize their relative power because that is the optimal way to maximize their security. In other words, survival mandates aggressive behavior. Great powers behave aggressively not because they want to or because they possess some inner drive to dominate, but because they have to seek more power if they want to maximize their odds of survival. (Table 1.1 summarizes how the main realist theories answer the foundational questions described above.)

No article or book makes the case for offensive realism in the sophisticated way that Morgenthau does for human nature realism and Waltz and others do for defensive realism. For sure, some realists have argued that the system gives great powers good reasons to act aggressively. Probably the best brief for offensive realism is a short, obscure book written during World War I by G. Lowes Dickinson, a British academic who was an early advocate of the League of Nations.⁴⁷ In The European Anarchy, he argues that the root cause of World War I “was not Germany nor any other power. The real culprit was the European anarchy,” which created powerful incentives for states “to acquire supremacy over the others for motives at once of security and domination.”⁴⁸ Nevertheless, neither Dickinson nor anyone else makes a comprehensive case for offensive realism.⁴⁹ My aim in writing this book is to fill that void.

 

POWER POLITICS IN LIBERAL AMERICA

Whatever merits realism may have as an explanation for real-world politics and as a guide for formulating foreign policy, it is not a popular school of thought in the West. Realism’s central message—that it makes good sense for states to selfishly pursue power—does not have broad appeal. It is difficult to imagine a modern political leader openly asking the public to fight and die to improve the balance of power. No European or American leader did so during either world war or the Cold War. Most people prefer to think of fights between their own state and rival states as clashes between good and evil, where they are on the side of the angels and their opponents are aligned with the devil. Thus, leaders tend to portray war as a moral crusade or an ideological contest, rather than as a struggle for power. Realism is a hard sell.

Americans appear to have an especially intense antipathy toward balance-of-power thinking. The rhetoric of twentieth-century presidents, for example, is filled with examples of realism bashing. Woodrow Wilson is probably the most well-known example of this tendency, because of his eloquent campaign against balance-of-power politics during and immediately after World War I.⁵⁰ Yet Wilson is hardly unique, and his successors have frequently echoed his views. In the final year of World War II, for example, Franklin Delano Roosevelt declared, “In the future world the misuse of power as implied in the term ‘power politics’ must not be the controlling factor in international relations.”⁵¹ More recently, Bill Clinton offered a strikingly similar view, proclaiming that “in a world where freedom, not tyranny, is on the march, the cynical calculus of pure power politics simply does not compute. It is ill-suited to a new era.”⁵² He sounded the same theme when defending NATO expansion in 1997, arguing that the charge that this policy might isolate Russia was based on the mistaken belief “that the great power territorial politics of the 20th century will dominate the 21st century.” Instead, Clinton emphasized his belief that “enlightened self-interest, as well as shared values, will compel countries to define their greatness in more constructive ways…and will compel us to cooperate.”⁵³

Why Americans Dislike Realism

Americans tend to be hostile to realism because it clashes with their basic values. Realism stands opposed to Americans’ views of both themselves and the wider world.⁵⁴ In particular, realism is at odds with the deep-seated sense of optimism and moralism that pervades much of American society. Liberalism, on the other hand, fits neatly with those values. Not surprisingly, foreign policy discourse in the United States often sounds as if it has been lifted right out of a Liberalism 101 lecture.

Americans are basically optimists.⁵⁵ They regard progress in politics, whether at the national or the international level, as both desirable and possible. As the French author Alexis de Tocqueville observed long ago, Americans believe that “man is endowed with an indefinite faculty of improvement.”⁵⁶ Realism, by contrast, offers a pessimistic perspective on international politics. It depicts a world rife with security competition and war, and holds out little promise of an “escape from the evil of power, regardless of what one does.”⁵⁷ Such pessimism is at odds with the powerful American belief that with time and effort, reasonable individuals can cooperate to solve important social problems.⁵⁸ Liberalism offers a more hopeful perspective on world politics, and Americans naturally find it more attractive than the gloomy specter drawn by realism.

Americans are also prone to believe that morality should play an important role in politics. As the prominent sociologist Seymour Martin Lipset writes, “Americans are utopian moralists who press hard to institutionalize virtue, to destroy evil people, and eliminate wicked institutions and practices.”⁵⁹ This perspective clashes with the realist belief that war is an intrinsic element of life in the international system. Most Americans tend to think of war as a hideous enterprise that should ultimately be abolished from the face of the Earth. It might justifiably be used for lofty liberal goals like fighting tyranny or spreading democracy, but it is morally incorrect to fight wars merely to change or preserve the balance of power. This makes the Clausewitzian conception of warfare anathema to most Americans.⁶⁰

The American proclivity for moralizing also conflicts with the fact that realists tend not to distinguish between good and bad states, but instead discriminate between states largely on the basis of their relative power capabilities. A purely realist interpretation of the Cold War, for example, allows for no meaningful difference in the motives behind American and Soviet behavior during that conflict. According to realist theory, both sides were driven by their concerns about the balance of power, and each did what it could to maximize its relative power. Most Americans would recoil at this interpretation of the Cold War, however, because they believe the United States was motivated by good intentions while the Soviet Union was not.

Liberal theorists do distinguish between good and bad states, of course, and they usually identify liberal democracies with market economies as the most worthy. Not surprisingly, Americans tend to like this perspective, because it identifies the United States as a benevolent force in world politics and portrays its real and potential rivals as misguided or malevolent troublemakers. Predictably, this line of thinking fueled the euphoria that attended the downfall of the Soviet Union and the end of the Cold War. When the “evil empire” collapsed, many Americans (and Europeans) concluded that democracy would spread across the globe and that world peace would soon break out. This optimism was based largely on the belief that democratic America is a virtuous state. If other states emulated the United States, therefore, the world would be populated by good states, and this development could only mean the end of international conflict.

Rhetoric vs. Practice

Because Americans dislike realpolitik, public discourse about foreign policy in the United States is usually couched in the language of liberalism. Hence the pronouncements of the policy elites are heavily flavored with optimism and moralism. American academics are especially good at promoting liberal thinking in the marketplace of ideas. Behind closed doors, however, the elites who make national security policy speak mostly the language of power, not that of principle, and the United States acts in the international system according to the dictates of realist logic.⁶¹ In essence, a discernible gap separates public rhetoric from the actual conduct of American foreign policy.

Prominent realists have often criticized U.S. diplomacy on the grounds that it is too idealistic and have complained that American leaders pay insufficient attention to the balance of power. For example, Kennan wrote in 1951, “I see the most serious fault of our past policy formulation to lie in something that I might call the legalistic-moralistic approach to international problems. This approach runs like a red skein through our foreign policy of the last fifty years.”⁶² According to this line of argument, there is no real gap between America’s liberal rhetoric and its foreign policy behavior, because the United States practices what it preaches. But this claim is wrong, as I will argue at length below. American foreign policy has usually been guided by realist logic, although the public pronouncements of its leaders might lead one to think otherwise.

It should be obvious to intelligent observers that the United States speaks one way and acts another. In fact, policymakers in other states have always remarked about this tendency in American foreign policy. As long ago as 1939, for example, Carr pointed out that states on the European continent regard the English-speaking peoples as “masters in the art of concealing their selfish national interests in the guise of the general good,” adding that “this kind of hypocrisy is a special and characteristic peculiarity of the Anglo-Saxon mind.”⁶³

Still, the gap between rhetoric and reality usually goes unnoticed in the United States itself. Two factors account for this phenomenon. First, realist policies sometimes coincide with the dictates of liberalism, in which case there is no conflict between the pursuit of power and the pursuit of principle. Under these circumstances, realist policies can be justified with liberal rhetoric without having to discuss the underlying power realities. This coincidence makes for an easy sell. For example, the United States fought against fascism in World War II and communism in the Cold War for largely realist reasons. But both of those fights were also consistent with liberal principles, and thus policymakers had little trouble selling them to the public as ideological conflicts.

Second, when power considerations force the United States to act in ways that conflict with liberal principles, “spin doctors” appear and tell a story that accords with liberal ideals.⁶⁴ For example, in the late nineteenth century, American elites generally considered Germany to be a progressive constitutional state worthy of emulation. But the American view of Germany changed in the decade before World War I, as relations between the two states deteriorated. By the time the United States declared war on Germany in April 1917, Americans had come to see Germany as more autocratic and militaristic than its European rivals.

Similarly, during the late 1930s, many Americans saw the Soviet Union as an evil state, partly in response to Josef Stalin’s murderous internal policies and his infamous alliance with Nazi Germany in August 1939. Nevertheless, when the United States joined forces with the Soviet Union in late 1941 to fight against the Third Reich, the U.S. government began a massive public relations campaign to clean up the image of America’s new ally and make it compatible with liberal ideals. The Soviet Union was now portrayed as a proto-democracy, and Stalin became “Uncle Joe.”

How is it possible to get away with this contradiction between rhetoric and policy? Most Americans readily accept these rationalizations because liberalism is so deeply rooted in their culture. As a result, they find it easy to believe that they are acting according to cherished principles, rather than cold and calculated power considerations.⁶⁵

THE PLAN OF THE BOOK

The rest of the chapters in this book are concerned mainly with answering the six big questions about power which I identified earlier. Chapter 2, which is probably the most important chapter in the book, lays out my theory of why states compete for power and why they pursue hegemony.

In Chapters 3 and 4, I define power and explain how to measure it. I do this in order to lay the groundwork for testing my theory. It is impossible to determine whether states have behaved according to the dictates of offensive realism without knowing what power is and what different strategies states employ to maximize their share of world power. My starting point is to distinguish between potential power and actual military power, and then to argue that states care deeply about both kinds of power. Chapter 3 focuses on potential power, which involves mainly the size of a state’s population and its wealth. Chapter 4 deals with actual military power. It is an especially long chapter because I make arguments about “the primacy of land power” and “the stopping power of water” that are novel and likely to be controversial.

In Chapter 5, I discuss the strategies that great powers employ to gain and maintain power. This chapter includes a substantial discussion of the utility of war for acquiring power. I also focus on balancing and buck-passing, which are the main strategies that states employ when faced with a rival that threatens to upset the balance of power.

In Chapters 6 and 7, I examine the historical record to see whether there is evidence to support the theory. Specifically, I compare the conduct of the great powers from 1792 to 1990 to see whether their behavior fits the predictions of offensive realism.

In Chapter 8, I lay out a simple theory that explains when great powers balance and when they choose to buck-pass, and then I examine that theory against the historical record. Chapter 9 focuses on the causes of war. Here, too, I lay out a simple theory and then test it against the empirical record.

Chapter 10 focuses on the rise of China, which is likely to be the most significant event in world politics over the course of the twenty-first century. Specifically, I address the all-important question: can China rise peacefully? I use my theory to predict how an increasingly powerful China is likely to interact with other countries in Asia and with the United States. My conclusion is bleak: there is likely to be an intense security competition between China and the United States, and most of China’s neighbors will balance with Washington against Beijing. In contrast to the predictions of many commentators, I also maintain that this security competition could easily lead to war.