Great powers, I argue, are always searching for opportunities to gain power over their rivals, with hegemony as their final goal. This perspective does not allow for status quo powers, except for the unusual state that achieves preponderance. Instead, the system is populated with great powers that have revisionist intentions at their core.1 This chapter presents a theory that explains this competition for power. Specifically, I attempt to show that there is a compelling logic behind my claim that great powers seek to maximize their share of world power. I do not, however, test offensive realism against the historical record in this chapter. That important task is reserved for later chapters.
WHY STATES PURSUE POWER
My explanation for why great powers vie with each other for power and strive for hegemony is derived from five assumptions about the international system. None of these assumptions alone mandates that states behave competitively. Taken together, however, they depict a world in which states have considerable reason to think and sometimes behave aggressively. In particular, the system encourages states to look for opportunities to maximize their power vis-à-vis other states.
How important is it that these assumptions be realistic? Some social scientists argue that the assumptions that underpin a theory need not conform to reality. Indeed, the economist Milton Friedman maintains that the best theories “will be found to have assumptions that are wildly inaccurate descriptive representations of reality, and, in general, the more significant the theory, the more unrealistic the assumptions.”2 According to this view, the explanatory power of a theory is all that matters. If unrealistic assumptions lead to a theory that tells us a lot about how the world works, it is of no importance whether the underlying assumptions are realistic or not.
I reject this view. Although I agree that explanatory power is the ultimate criterion for assessing theories, I also believe that a theory based on unrealistic or false assumptions will not explain much about how the world works.3 Sound theories are based on sound assumptions. Accordingly, each of these five assumptions is a reasonably accurate representation of an important aspect of life in the international system.
Bedrock Assumptions
The first assumption is that the international system is anarchic, which does not mean that it is chaotic or riven by disorder. It is easy to draw that conclusion, since realism depicts a world characterized by security competition and war. By itself, however, the realist notion of anarchy has nothing to do with conflict; it is an ordering principle, which says that the system comprises independent states that have no central authority above them.4 Sovereignty, in other words, inheres in states because there is no higher ruling body in the international system.5 There is no “government over governments.”6
The second assumption is that great powers inherently possess some offensive military capability, which gives them the wherewithal to hurt and possibly destroy each other. States are potentially dangerous to each other, although some states have more military might than others and are therefore more dangerous. A state’s military power is usually identified with the particular weaponry at its disposal, although even if there were no weapons, the individuals in those states could still use their feet and hands to attack the population of another state. After all, for every neck, there are two hands to choke it.
The third assumption is that states can never be certain about other states’ intentions. Specifically, no state can be sure that another state will not use its offensive military capability to attack the first state. This is not to say that states necessarily have hostile intentions. Indeed, all of the states in the system may be reliably benign, but it is impossible to be sure of that judgment because intentions are impossible to divine with 100 percent certainty.7 There are many possible causes of aggression, and no state can be sure that another state is not motivated by one of them.8 Furthermore, intentions can change quickly, so a state’s intentions can be benign one day and hostile the next. Uncertainty about intentions is unavoidable, which means that states can never be sure that other states do not have offensive intentions to go along with their offensive capabilities.
The fourth assumption is that survival is the primary goal of great powers. Specifically, states seek to maintain their territorial integrity and the autonomy of their domestic political order. Survival dominates other motives because, once a state is conquered, it is unlikely to be in a position to pursue other aims. Soviet leader Josef Stalin put the point well during a war scare in 1927: “We can and must build socialism in the [Soviet Union]. But in order to do so we first of all have to exist.”9 States can and do pursue other goals, of course, but security is their most important objective.
The fifth assumption is that great powers are rational actors. They are aware of their external environment and they think strategically about how to survive in it. In particular, they consider the preferences of other states and how their own behavior is likely to affect the behavior of those other states, and how the behavior of those other states is likely to affect their own strategy for survival. Moreover, states pay attention to the long term as well as the immediate consequences of their actions.
As emphasized, none of these assumptions alone dictates that great powers as a general rule should behave aggressively toward each other. There is surely the possibility that some state might have hostile intentions, but the only assumption dealing with a specific motive that is common to all states says that their principal objective is to survive, which by itself is a rather harmless goal. Nevertheless, when the five assumptions are married together, they create powerful incentives for great powers to think and act offensively with regard to each other. In particular, three general patterns of behavior result: fear, self-help, and power maximization.
State Behavior
Great powers fear each other. They regard each other with suspicion, and they worry that war might be in the offing. They anticipate danger. There is little room for trust among states. For sure, the level of fear varies across time and space, but it cannot be reduced to a trivial level. From the perspective of any one great power, all other great powers are potential enemies. This point is illustrated by the reaction of the United Kingdom and France to German reunification at the end of the Cold War. Despite the fact that these three states had been close allies for almost forty-five years, both the United Kingdom and France immediately began worrying about the potential dangers of a united Germany.10
The basis of this fear is that in a world where great powers have the capability to attack each other and might have the motive to do so, any state bent on survival must be at least suspicious of other states and reluctant to trust them. Add to this the “911” problem—the absence of a central authority to which a threatened state can turn for help—and states have even greater incentive to fear each other. Moreover, there is no mechanism, other than the possible self-interest of third parties, for punishing an aggressor. Because it is sometimes difficult to deter potential aggressors, states have ample reason not to trust other states and to be prepared for war with them.
The possible consequences of falling victim to aggression further amplify the importance of fear as a motivating force in world politics. Great powers do not compete with each other as if international politics were merely an economic marketplace. Political competition among states is a much more dangerous business than mere economic intercourse; the former can lead to war, and war often means mass killing on the battlefield as well as mass murder of civilians. In extreme cases, war can even lead to the destruction of states. The horrible consequences of war sometimes cause states to view each other not just as competitors, but as potentially deadly enemies. Political antagonism, in short, tends to be intense, because the stakes are great.
States in the international system also aim to guarantee their own survival. Because other states are potential threats, and because there is no higher authority to come to their rescue when they dial 911, states cannot depend on others for their own security. Each state tends to see itself as vulnerable and alone, and therefore it aims to provide for its own survival. In international politics, God helps those who help themselves. This emphasis on self-help does not preclude states from forming alliances.11 But alliances are only temporary marriages of convenience: today’s alliance partner might be tomorrow’s enemy, and today’s enemy might be tomorrow’s alliance partner. For example, the United States fought with China and the Soviet Union against Germany and Japan in World War II, but soon thereafter flip-flopped enemies and partners and allied with West Germany and Japan against China and the Soviet Union during the Cold War.
States operating in a self-help world almost always act according to their own self-interest and do not subordinate their interests to the interests of other states, or to the interests of the so-called international community. The reason is simple: it pays to be selfish in a self-help world. This is true in the short term as well as in the long term, because if a state loses in the short run, it might not be around for the long haul.
Apprehensive about the ultimate intentions of other states, and aware that they operate in a self-help system, states quickly understand that the best way to ensure their survival is to be the most powerful state in the system. The stronger a state is relative to its potential rivals, the less likely it is that any of those rivals will attack it and threaten its survival. Weaker states will be reluctant to pick fights with more powerful states because the weaker states are likely to suffer military defeat. Indeed, the bigger the gap in power between any two states, the less likely it is that the weaker will attack the stronger. Neither Canada nor Mexico, for example, would countenance attacking the United States, which is far more powerful than its neighbors. The ideal situation is to be the hegemon in the system. As Immanuel Kant said, “It is the desire of every state, or of its ruler, to arrive at a condition of perpetual peace by conquering the whole world, if that were possible.”12 Survival would then be almost guaranteed.13
Consequently, states pay close attention to how power is distributed among them, and they make a special effort to maximize their share of world power. Specifically, they look for opportunities to alter the balance of power by acquiring additional increments of power at the expense of potential rivals. States employ a variety of means—economic, diplomatic, and military—to shift the balance of power in their favor, even if doing so makes other states suspicious or even hostile. Because one state’s gain in power is another state’s loss, great powers tend to have a zero-sum mentality when dealing with each other. The trick, of course, is to be the winner in this competition and to dominate the other states in the system. Thus, the claim that states maximize relative power is tantamount to arguing that states are disposed to think offensively toward other states, even though their ultimate motive is simply to survive. In short, great powers have aggressive intentions.14
Even when a great power achieves a distinct military advantage over its rivals, it continues looking for chances to gain more power. The pursuit of power stops only when hegemony is achieved. The idea that a great power might feel secure without dominating the system, provided it has an “appropriate amount” of power, is not persuasive, for two reasons.15 First, it is difficult to assess how much relative power one state must have over its rivals before it is secure. Is twice as much power an appropriate threshold? Or is three times as much power the magic number? The root of the problem is that power calculations alone do not determine which side wins a war. Clever strategies, for example, sometimes allow less powerful states to defeat more powerful foes.
Second, determining how much power is enough becomes even more complicated when great powers contemplate how power will be distributed among them ten or twenty years down the road. The capabilities of individual states vary over time, sometimes markedly, and it is often difficult to predict the direction and scope of change in the balance of power. Remember, few in the West anticipated the collapse of the Soviet Union before it happened. In fact, during the first half of the Cold War, many in the West feared that the Soviet economy would eventually generate greater wealth than the American economy, which would cause a marked power shift against the United States and its allies. What the future holds for China and Russia and what the balance of power will look like in 2020 is difficult to foresee.
Given the difficulty of determining how much power is enough for today and tomorrow, great powers recognize that the best way to ensure their security is to achieve hegemony now, thus eliminating any possibility of a challenge by another great power. Only a misguided state would pass up an opportunity to be the hegemon in the system because it thought it already had sufficient power to survive.16 But even if a great power does not have the wherewithal to achieve hegemony (and that is usually the case), it will still act offensively to amass as much power as it can, because states are almost always better off with more rather than less power. In short, states do not become status quo powers until they completely dominate the system.
All states are influenced by this logic, which means that not only do they look for opportunities to take advantage of one another, they also work to ensure that other states do not take advantage of them. After all, rival states are driven by the same logic, and most states are likely to recognize their own motives at play in the actions of other states. In short, states ultimately pay attention to defense as well as offense. They think about conquest themselves, and they work to check aggressor states from gaining power at their expense. This inexorably leads to a world of constant security competition, where states are willing to lie, cheat, and use brute force if it helps them gain advantage over their rivals. Peace, if one defines that concept as a state of tranquility or mutual concord, is not likely to break out in this world.
The “security dilemma,” which is one of the most well-known concepts in the international relations literature, reflects the basic logic of offensive realism. The essence of the dilemma is that the measures a state takes to increase its own security usually decrease the security of other states. Thus, it is difficult for a state to increase its own chances of survival without threatening the survival of other states. John Herz first introduced the security dilemma in a 1950 article in the journal World Politics.17 After discussing the anarchic nature of international politics, he writes, “Striving to attain security from…attack, [states] are driven to acquire more and more power in order to escape the impact of the power of others. This, in turn, renders the others more insecure and compels them to prepare for the worst. Since none can ever feel entirely secure in such a world of competing units, power competition ensues, and the vicious circle of security and power accumulation is on.”18 The implication of Herz’s analysis is clear: the best way for a state to survive in anarchy is to take advantage of other states and gain power at their expense. The best defense is a good offense. Since this message is widely understood, ceaseless security competition ensues. Unfortunately, little can be done to ameliorate the security dilemma as long as states operate in anarchy.
It should be apparent from this discussion that saying that states are power maximizers is tantamount to saying that they care about relative power, not absolute power. There is an important distinction here, because states concerned about relative power behave differently than do states interested in absolute power.19 States that maximize relative power are concerned primarily with the distribution of material capabilities. In particular, they try to gain as large a power advantage as possible over potential rivals, because power is the best means to survival in a dangerous world. Thus, states motivated by relative power concerns are likely to forgo large gains in their own power, if such gains give rival states even greater power, for smaller national gains that nevertheless provide them with a power advantage over their rivals.20 States that maximize absolute power, on the other hand, care only about the size of their own gains, not those of other states. They are not motivated by balance-of-power logic but instead are concerned with amassing power without regard to how much power other states control. They would jump at the opportunity for large gains, even if a rival gained more in the deal. Power, according to this logic, is not a means to an end (survival), but an end in itself.21
Calculated Aggression
There is obviously little room for status quo powers in a world where states are inclined to look for opportunities to gain more power. Nevertheless, great powers cannot always act on their offensive intentions, because behavior is influenced not only by what states want, but also by their capacity to realize these desires. Every state might want to be king of the hill, but not every state has the wherewithal to compete for that lofty position, much less achieve it. Much depends on how military might is distributed among the great powers. A great power that has a marked power advantage over its rivals is likely to behave more aggressively, because it has the capability as well as the incentive to do so.
By contrast, great powers facing powerful opponents will be less inclined to consider offensive action and more concerned with defending the existing balance of power from threats by their more powerful opponents. Let there be an opportunity for those weaker states to revise the balance in their own favor, however, and they will take advantage of it. Stalin put the point well at the end of World War II: “Everyone imposes his own system as far as his army can reach. It cannot be otherwise.”22 States might also have the capability to gain advantage over a rival power but nevertheless decide that the perceived costs of offense are too high and do not justify the expected benefits.
In short, great powers are not mindless aggressors so bent on gaining power that they charge headlong into losing wars or pursue Pyrrhic victories. On the contrary, before great powers take offensive actions, they think carefully about the balance of power and about how other states will react to their moves. They weigh the costs and risks of offense against the likely benefits. If the benefits do not outweigh the risks, they sit tight and wait for a more propitious moment. Nor do states start arms races that are unlikely to improve their overall position. As discussed at greater length in Chapter 3, states sometimes limit defense spending either because spending more would bring no strategic advantage or because spending more would weaken the economy and undermine the state’s power in the long run.23 To paraphrase Clint Eastwood, a state has to know its limitations to survive in the international system.
Nevertheless, great powers miscalculate from time to time because they invariably make important decisions on the basis of imperfect information. States hardly ever have complete information about any situation they confront. There are two dimensions to this problem. Potential adversaries have incentives to misrepresent their own strength or weakness, and to conceal their true aims.24 For example, a weaker state trying to deter a stronger state is likely to exaggerate its own power to discourage the potential aggressor from attacking. On the other hand, a state bent on aggression is likely to emphasize its peaceful goals while exaggerating its military weakness, so that the potential victim does not build up its own arms and thus leaves itself vulnerable to attack. Probably no national leader was better at practicing this kind of deception than Adolf Hitler.
But even if disinformation was not a problem, great powers are often unsure about how their own military forces, as well as the adversary’s, will perform on the battlefield. For example, it is sometimes difficult to determine in advance how new weapons and untested combat units will perform in the face of enemy fire. Peacetime maneuvers and war games are helpful but imperfect indicators of what is likely to happen in actual combat. Fighting wars is a complicated business in which it is often difficult to predict outcomes. Remember that although the United States and its allies scored a stunning and remarkably easy victory against Iraq in early 1991, most experts at the time believed that Iraq’s military would be a formidable foe and put up stubborn resistance before finally succumbing to American military might.25
Great powers are also sometimes unsure about the resolve of opposing states as well as allies. For example, Germany believed that if it went to war against France and Russia in the summer of 1914, the United Kingdom would probably stay out of the fight. Saddam Hussein expected the United States to stand aside when he invaded Kuwait in August 1990. Both aggressors guessed wrong, but each had good reason to think that its initial judgment was correct. In the 1930s, Adolf Hitler believed that his great-power rivals would be easy to exploit and isolate because each had little interest in fighting Germany and instead was determined to get someone else to assume that burden. He guessed right. In short, great powers constantly find themselves confronting situations in which they have to make important decisions with incomplete information. Not surprisingly, they sometimes make faulty judgments and end up doing themselves serious harm.
Some defensive realists go so far as to suggest that the constraints of the international system are so powerful that offense rarely succeeds, and that aggressive great powers invariably end up being punished.26 As noted, they emphasize that 1) threatened states balance against aggressors and ultimately crush them, and 2) there is an offense-defense balance that is usually heavily tilted toward the defense, thus making conquest especially difficult. Great powers, therefore, should be content with the existing balance of power and not try to change it by force. After all, it makes little sense for a state to initiate a war that it is likely to lose; that would be self-defeating behavior. It is better to concentrate instead on preserving the balance of power.27 Moreover, because aggressors seldom succeed, states should understand that security is abundant, and thus there is no good strategic reason for wanting more power in the first place. In a world where conquest seldom pays, states should have relatively benign intentions toward each other. If they do not, these defensive realists argue, the reason is probably poisonous domestic politics, not smart calculations about how to guarantee one’s security in an anarchic world.
There is no question that systemic factors constrain aggression, especially balancing by threatened states. But defensive realists exaggerate those restraining forces.28 Indeed, the historical record provides little support for their claim that offense rarely succeeds. One study estimates that there were 63 wars between 1815 and 1980, and the initiator won 39 times, which translates into about a 60 percent success rate.29 Turning to specific cases, Otto von Bismarck unified Germany by winning military victories against Denmark in 1864, Austria in 1866, and France in 1870, and the United States as we know it today was created in good part by conquest in the nineteenth century. Conquest certainly paid big dividends in these cases. Nazi Germany won wars against Poland in 1939 and France in 1940, but lost to the Soviet Union between 1941 and 1945. Conquest ultimately did not pay for the Third Reich, but if Hitler had restrained himself after the fall of France and had not invaded the Soviet Union, conquest probably would have paid handsomely for the Nazis. In short, the historical record shows that offense sometimes succeeds and sometimes does not. The trick for a sophisticated power maximizer is to figure out when to raise and when to fold.30
HEGEMONY’S LIMITS
Great powers, as I have emphasized, strive to gain power over their rivals and hopefully become hegemons. Once a state achieves that exalted position, it becomes a status quo power. More needs to be said, however, about the meaning of hegemony.
A hegemon is a state that is so powerful that it dominates all the other states in the system.31 No other state has the military wherewithal to put up a serious fight against it. In essence, a hegemon is the only great power in the system. A state that is substantially more powerful than the other great powers in the system is not a hegemon, because it faces, by definition, other great powers. The United Kingdom in the mid-nineteenth century, for example, is sometimes called a hegemon. But it was not a hegemon, because there were four other great powers in Europe at the time—Austria, France, Prussia, and Russia—and the United Kingdom did not dominate them in any meaningful way. In fact, during that period, the United Kingdom considered France to be a serious threat to the balance of power. Europe in the nineteenth century was multipolar, not unipolar.
Hegemony means domination of the system, which is usually interpreted to mean the entire world. It is possible, however, to apply the concept of a system more narrowly and use it to describe particular regions, such as Europe, Northeast Asia, and the Western Hemisphere. Thus, one can distinguish between global hegemons, which dominate the world, and regional hegemons, which dominate distinct geographical areas. The United States has been a regional hegemon in the Western Hemisphere for at least the past one hundred years. No other state in the Americas has sufficient military might to challenge it, which is why the United States is widely recognized as the only great power in its region.
My argument, which I develop at length in subsequent chapters, is that except for the unlikely event wherein one state achieves clear-cut nuclear superiority, it is virtually impossible for any state to achieve global hegemony. The principal impediment to world domination is the difficulty of projecting power across the world’s oceans onto the territory of a rival great power. The United States, for example, is the most powerful state on the planet today. But it does not dominate Europe and Northeast Asia the way it does the Western Hemisphere, and it has no intention of trying to conquer and control those distant regions, mainly because of the stopping power of water. Indeed, there is reason to think that the American military commitment to Europe and Northeast Asia might wither away over the next decade. In short, there has never been a global hegemon, and there is not likely to be one anytime soon.
The best outcome a great power can hope for is to be a regional hegemon and possibly control another region that is nearby and accessible over land. The United States is the only regional hegemon in modern history, although other states have fought major wars in pursuit of regional hegemony: imperial Japan in Northeast Asia, and Napoleonic France, Wilhelmine Germany, and Nazi Germany in Europe. But none succeeded. The Soviet Union, which is located in Europe and Northeast Asia, threatened to dominate both of those regions during the Cold War. The Soviet Union might also have attempted to conquer the oil-rich Persian Gulf region, with which it shared a border. But even if Moscow had been able to dominate Europe, Northeast Asia, and the Persian Gulf, which it never came close to doing, it still would have been unable to conquer the Western Hemisphere and become a true global hegemon.
States that achieve regional hegemony seek to prevent great powers in other regions from duplicating their feat. Regional hegemons, in other words, do not want peers. Thus the United States, for example, played a key role in preventing imperial Japan, Wilhelmine Germany, Nazi Germany, and the Soviet Union from gaining regional supremacy. Regional hegemons attempt to check aspiring hegemons in other regions because they fear that a rival great power that dominates its own region will be an especially powerful foe that is essentially free to cause trouble in the fearful great power’s backyard. Regional hegemons prefer that there be at least two great powers located together in other regions, because their proximity will force them to concentrate their attention on each other rather than on the distant hegemon.
Furthermore, if a potential hegemon emerges among them, the other great powers in that region might be able to contain it by themselves, allowing the distant hegemon to remain safely on the sidelines. Of course, if the local great powers were unable to do the job, the distant hegemon would take the appropriate measures to deal with the threatening state. The United States, as noted, has assumed that burden on four separate occasions in the twentieth century, which is why it is commonly referred to as an “offshore balancer.”
In sum, the ideal situation for any great power is to be the only regional hegemon in the world. That state would be a status quo power, and it would go to considerable lengths to preserve the existing distribution of power. The United States is in that enviable position today; it dominates the Western Hemisphere and there is no hegemon in any other area of the world. But if a regional hegemon is confronted with a peer competitor, it would no longer be a status quo power. Indeed, it would go to considerable lengths to weaken and maybe even destroy its distant rival. Of course, both regional hegemons would be motivated by that logic, which would make for a fierce security competition between them.
POWER AND FEAR
That great powers fear each other is a central aspect of life in the international system. But as noted, the level of fear varies from case to case. For example, the Soviet Union worried much less about Germany in 1930 than it did in 1939. How much states fear each other matters greatly, because the amount of fear between them largely determines the severity of their security competition, as well as the probability that they will fight a war. The more profound the fear is, the more intense is the security competition, and the more likely is war. The logic is straightforward: a scared state will look especially hard for ways to enhance its security, and it will be disposed to pursue risky policies to achieve that end. Therefore, it is important to understand what causes states to fear each other more or less intensely.
Fear among great powers derives from the fact that they invariably have some offensive military capability that they can use against each other, and the fact that one can never be certain that other states do not intend to use that power against oneself. Moreover, because states operate in an anarchic system, there is no night watchman to whom they can turn for help if another great power attacks them. Although anarchy and uncertainty about other states’ intentions create an irreducible level of fear among states that leads to power-maximizing behavior, they cannot account for why sometimes that level of fear is greater than at other times. The reason is that anarchy and the difficulty of discerning state intentions are constant facts of life, and constants cannot explain variation. The capability that states have to threaten each other, however, varies from case to case, and it is the key factor that drives fear levels up and down. Specifically, the more power a state possesses, the more fear it generates among its rivals. Germany, for example, was much more powerful at the end of the 1930s than it was at the decade’s beginning, which is why the Soviets became increasingly fearful of Germany over the course of that decade.
This discussion of how power affects fear prompts the question, What is power? It is important to distinguish between potential and actual power. A state’s potential power is based on the size of its population and the level of its wealth. These two assets are the main building blocks of military power. Wealthy rivals with large populations can usually build formidable military forces. A state’s actual power is embedded mainly in its army and the air and naval forces that directly support it. Armies are the central ingredient of military power, because they are the principal instrument for conquering and controlling territory—the paramount political objective in a world of territorial states. In short, the key component of military might, even in the nuclear age, is land power.
Power considerations affect the intensity of fear among states in three main ways. First, rival states that possess nuclear forces that can survive a nuclear attack and retaliate against it are likely to fear each other less than if these same states had no nuclear weapons. During the Cold War, for example, the level of fear between the superpowers probably would have been substantially greater if nuclear weapons had not been invented. The logic here is simple: because nuclear weapons can inflict devastating destruction on a rival state in a short period of time, nuclear-armed rivals are going to be reluctant to fight with each other, which means that each side will have less reason to fear the other than would otherwise be the case. But as the Cold War demonstrates, this does not mean that war between nuclear powers is no longer thinkable; they still have reason to fear each other.
Second, when great powers are separated by large bodies of water, they usually do not have much offensive capability against each other, regardless of the relative size of their armies. Large bodies of water are formidable obstacles that cause significant power-projection problems for attacking armies. For example, the stopping power of water explains in good part why the United Kingdom and the United States (since becoming a great power in 1898) have never been invaded by another great power. It also explains why the United States has never tried to conquer territory in Europe or Northeast Asia, and why the United Kingdom has never attempted to dominate the European continent. Great powers located on the same landmass are in a much better position to attack and conquer each other. That is especially true of states that share a common border. Therefore, great powers separated by water are likely to fear each other less than great powers that can get at each other over land.
Third, the distribution of power among the states in the system also markedly affects the levels of fear.32 The key issue is whether power is distributed more or less evenly among the great powers or whether there are sharp power asymmetries. The configuration of power that generates the most fear is a multipolar system that contains a potential hegemon—what I call “unbalanced multipolarity.”
A potential hegemon is more than just the most powerful state in the system. It is a great power with so much actual military capability and so much potential power that it stands a good chance of dominating and controlling all of the other great powers in its region of the world. A potential hegemon need not have the wherewithal to fight all of its rivals at once, but it must have excellent prospects of defeating each opponent alone, and good prospects of defeating some of them in tandem. The key relationship, however, is the power gap between the potential hegemon and the second most powerful state in the system: there must be a marked gap between them. To qualify as a potential hegemon, a state must have—by some reasonably large margin—the most formidable army as well as the most latent power among all the states located in its region.
Bipolarity is the power configuration that produces the least amount of fear among the great powers, although not a negligible amount by any means. Fear tends to be less acute in bipolarity, because there is usually a rough balance of power between the two major states in the system. Multipolar systems without a potential hegemon, what I call “balanced multipolarity,” are still likely to have power asymmetries among their members, although these asymmetries will not be as pronounced as the gaps created by the presence of an aspiring hegemon. Therefore, balanced multipolarity is likely to generate less fear than unbalanced multipolarity, but more fear than bipolarity.
This discussion of how the level of fear between great powers varies with changes in the distribution of power, not with assessments about each other’s intentions, raises a related point. When a state surveys its environment to determine which states pose a threat to its survival, it focuses mainly on the offensive capabilities of potential rivals, not their intentions. As emphasized earlier, intentions are ultimately unknowable, so states worried about their survival must make worst-case assumptions about their rivals’ intentions. Capabilities, however, not only can be measured but also determine whether or not a rival state is a serious threat. In short, great powers balance against capabilities, not intentions.33
Great powers obviously balance against states with formidable military forces, because that offensive military capability is the tangible threat to their survival. But great powers also pay careful attention to how much latent power rival states control, because rich and populous states usually can and do build powerful armies. Thus, great powers tend to fear states with large populations and rapidly expanding economies, even if these states have not yet translated their wealth into military might.
THE HIERARCHY OF STATE GOALS
Survival is the number one goal of great powers, according to my theory. In practice, however, states pursue non-security goals as well. For example, great powers invariably seek greater economic prosperity to enhance the welfare of their citizenry. They sometimes seek to promote a particular ideology abroad, as happened during the Cold War when the the United States tried to spread democracy around the world and the Soviet Union tried to sell communism. National unification is another goal that sometimes motivates states, as it did with Prussia and Italy in the nineteenth century and Germany after the Cold War. Great powers also occasionally try to foster human rights around the globe. States might pursue any of these, as well as a number of other non-security goals.
Offensive realism certainly recognizes that great powers might pursue these non-security goals, but it has little to say about them, save for one important point: states can pursue them as long as the requisite behavior does not conflict with balance-of-power logic, which is often the case.34 Indeed, the pursuit of these non-security goals sometimes complements the hunt for relative power. For example, Nazi Germany expanded into eastern Europe for both ideological and realist reasons, and the superpowers competed with each other during the Cold War for similar reasons. Furthermore, greater economic prosperity invariably means greater wealth, which has significant implications for security, because wealth is the foundation of military power. Wealthy states can afford powerful military forces, which enhance a state’s prospects for survival. As the political economist Jacob Viner noted more than fifty years ago, “there is a long-run harmony” between wealth and power.35 National unification is another goal that usually complements the pursuit of power. For example, the unified German state that emerged in 1871 was more powerful than the Prussian state it replaced.
Sometimes the pursuit of non-security goals has hardly any effect on the balance of power, one way or the other. Human rights interventions usually fit this description, because they tend to be small-scale operations that cost little and do not detract from a great power’s prospects for survival. For better or for worse, states are rarely willing to expend blood and treasure to protect foreign populations from gross abuses, including genocide. For instance, despite claims that American foreign policy is infused with moralism, Somalia (1992–93) is the only instance during the past one hundred years in which U.S. soldiers were killed in action on a humanitarian mission. And in that case, the loss of a mere eighteen soldiers in an infamous firefight in October 1993 so traumatized American policymakers that they immediately pulled all U.S. troops out of Somalia and then refused to intervene in Rwanda in the spring of 1994, when ethnic Hutu went on a genocidal rampage against their Tutsi neighbors.36 Stopping that genocide would have been relatively easy and it would have had virtually no effect on the position of the United States in the balance of power.37 Yet nothing was done. In short, although realism does not prescribe human rights interventions, it does not necessarily proscribe them.
But sometimes the pursuit of non-security goals conflicts with balance-of-power logic, in which case states usually act according to the dictates of realism. For example, despite the U.S. commitment to spreading democracy across the globe, it helped overthrow democratically elected governments and embraced a number of authoritarian regimes during the Cold War, when American policymakers felt that these actions would help contain the Soviet Union.38 In World War II, the liberal democracies put aside their antipathy for communism and formed an alliance with the Soviet Union against Nazi Germany. “I can’t take communism,” Franklin Roosevelt emphasized, but to defeat Hitler “I would hold hands with the Devil.”39 In the same way, Stalin repeatedly demonstrated that when his ideological preferences clashed with power considerations, the latter won out. To take the most blatant example of his realism, the Soviet Union formed a non-aggression pact with Nazi Germany in August 1939—the infamous Molotov-Ribbentrop Pact—in hopes that the agreement would at least temporarily satisfy Hitler’s territorial ambitions in eastern Europe and turn the Wehrmacht toward France and the United Kingdom.40 When great powers confront a serious threat, in short, they pay little attention to ideology as they search for alliance partners.41
Security also trumps wealth when those two goals conflict, because “defence,” as Adam Smith wrote in The Wealth of Nations, “is of much more importance than opulence.”42 Smith provides a good illustration of how states behave when forced to choose between wealth and relative power. In 1651, England put into effect the famous Navigation Act, protectionist legislation designed to damage Holland’s commerce and ultimately cripple the Dutch economy. The legislation mandated that all goods imported into England be carried either in English ships or ships owned by the country that originally produced the goods. Since the Dutch produced few goods themselves, this measure would badly damage their shipping, the central ingredient in their economic success. Of course, the Navigation Act would hurt England’s economy as well, mainly because it would rob England of the benefits of free trade. “The act of navigation,” Smith wrote, “is not favorable to foreign commerce, or to the growth of that opulence that can arise from it.” Nevertheless, Smith considered the legislation “the wisest of all the commercial regulations of England” because it did more damage to the Dutch economy than to the English economy, and in the mid-seventeenth century Holland was “the only naval power which could endanger the security of England.”43
CREATING WORLD ORDER
The claim is sometimes made that great powers can transcend realist logic by working together to build an international order that fosters peace and justice. World peace, it would appear, can only enhance a state’s prosperity and security. America’s political leaders paid considerable lip service to this line of argument over the course of the twentieth century. President Clinton, for example, told an audience at the United Nations in September 1993 that “at the birth of this organization 48 years ago…a generation of gifted leaders from many nations stepped forward to organize the world’s efforts on behalf of security and prosperity…. Now history has granted to us a moment of even greater opportunity…. Let us resolve that we will dream larger…. Let us ensure that the world we pass to our children is healthier, safer and more abundant than the one we inhabit today.”44
This rhetoric notwithstanding, great powers do not work together to promote world order for its own sake. Instead, each seeks to maximize its own share of world power, which is likely to clash with the goal of creating and sustaining stable international orders.45 This is not to say that great powers never aim to prevent wars and keep the peace. On the contrary, they work hard to deter wars in which they would be the likely victim. In such cases, however, state behavior is driven largely by narrow calculations about relative power, not by a commitment to build a world order independent of a state’s own interests. The United States, for example, devoted enormous resources to deterring the Soviet Union from starting a war in Europe during the Cold War, not because of some deep-seated commitment to promoting peace around the world, but because American leaders feared that a Soviet victory would lead to a dangerous shift in the balance of power.46
The particular international order that obtains at any time is mainly a by-product of the self-interested behavior of the system’s great powers. The configuration of the system, in other words, is the unintended consequence of great-power security competition, not the result of states acting together to organize peace. The establishment of the Cold War order in Europe illustrates this point. Neither the Soviet Union nor the United States intended to establish it, nor did they work together to create it. In fact, each superpower worked hard in the early years of the Cold War to gain power at the expense of the other, while preventing the other from doing likewise.47 The system that emerged in Europe in the aftermath of World War II was the unplanned consequence of intense security competition between the superpowers.
Although that intense superpower rivalry ended along with the Cold War in 1990, Russia and the United States have not worked together to create the present order in Europe. The United States, for example, has rejected out of hand various Russian proposals to make the Organization for Security and Cooperation in Europe the central organizing pillar of European security (replacing the U.S.-dominated NATO). Furthermore, Russia was deeply opposed to NATO expansion, which it viewed as a serious threat to Russian security. Recognizing that Russia’s weakness would preclude any retaliation, however, the United States ignored Russia’s concerns and pushed NATO to accept the Czech Republic, Hungary, and Poland as new members. Russia has also opposed U.S. policy in the Balkans over the past decade, especially NATO’s 1999 war against Yugoslavia. Again, the United States has paid little attention to Russia’s concerns and has taken the steps it deems necessary to bring peace to that volatile region. Finally, it is worth noting that although Russia is dead set against allowing the United States to deploy ballistic missile defenses, it is highly likely that Washington will deploy such a system if it is judged to be technologically feasible.
For sure, great-power rivalry will sometimes produce a stable international order, as happened during the Cold War. Nevertheless, the great powers will continue looking for opportunities to increase their share of world power, and if a favorable situation arises, they will move to undermine that stable order. Consider how hard the United States worked during the late 1980s to weaken the Soviet Union and bring down the stable order that had emerged in Europe during the latter part of the Cold War.48 Of course, the states that stand to lose power will work to deter aggression and preserve the existing order. But their motives will be selfish, revolving around balance-of-power logic, not some commitment to world peace.
Great powers cannot commit themselves to the pursuit of a peaceful world order for two reasons. First, states are unlikely to agree on a general formula for bolstering peace. Certainly, international relations scholars have never reached a consensus on what the blueprint should look like. In fact, it seems there are about as many theories on the causes of war and peace as there are scholars studying the subject. But more important, policymakers are unable to agree on how to create a stable world. For example, at the Paris Peace Conference after World War I, important differences over how to create stability in Europe divided Georges Clemenceau, David Lloyd George, and Woodrow Wilson.49 In particular, Clemenceau was determined to impose harsher terms on Germany over the Rhineland than was either Lloyd George or Wilson, while Lloyd George stood out as the hard-liner on German reparations. The Treaty of Versailles, not surprisingly, did little to promote European stability.
Furthermore, consider American thinking on how to achieve stability in Europe in the early days of the Cold War.50 The key elements for a stable and durable system were in place by the early 1950s. They included the division of Germany, the positioning of American ground forces in Western Europe to deter a Soviet attack, and ensuring that West Germany would not seek to develop nuclear weapons. Officials in the Truman administration, however, disagreed about whether a divided Germany would be a source of peace or war. For example, George Kennan and Paul Nitze, who held important positions in the State Department, believed that a divided Germany would be a source of instability, whereas Secretary of State Dean Acheson disagreed with them. In the 1950s, President Eisenhower sought to end the American commitment to defend Western Europe and to provide West Germany with its own nuclear deterrent. This policy, which was never fully adopted, nevertheless caused significant instability in Europe, as it led directly to the Berlin crises of 1958–59 and 1961.51
Second, great powers cannot put aside power considerations and work to promote international peace because they cannot be sure that their efforts will succeed. If their attempt fails, they are likely to pay a steep price for having neglected the balance of power, because if an aggressor appears at the door there will be no answer when they dial 911. That is a risk few states are willing to run. Therefore, prudence dictates that they behave according to realist logic. This line of reasoning accounts for why collective security schemes, which call for states to put aside narrow concerns about the balance of power and instead act in accordance with the broader interests of the international community, invariably die at birth.52
COOPERATION AMONG STATES
One might conclude from the preceding discussion that my theory does not allow for any cooperation among the great powers. But this conclusion would be wrong. States can cooperate, although cooperation is sometimes difficult to achieve and always difficult to sustain. Two factors inhibit cooperation: considerations about relative gains and concern about cheating.53 Ultimately, great powers live in a fundamentally competitive world where they view each other as real, or at least potential, enemies, and they therefore look to gain power at each other’s expense.
Any two states contemplating cooperation must consider how profits or gains will be distributed between them. They can think about the division in terms of either absolute or relative gains (recall the distinction made earlier between pursuing either absolute power or relative power; the concept here is the same). With absolute gains, each side is concerned with maximizing its own profits and cares little about how much the other side gains or loses in the deal. Each side cares about the other only to the extent that the other side’s behavior affects its own prospects for achieving maximum profits. With relative gains, on the other hand, each side considers not only its own individual gain, but also how well it fares compared to the other side.
Because great powers care deeply about the balance of power, their thinking focuses on relative gains when they consider cooperating with other states. For sure, each state tries to maximize its absolute gains; still, it is more important for a state to make sure that it does no worse, and perhaps better, than the other state in any agreement. Cooperation is more difficult to achieve, however, when states are attuned to relative gains rather than absolute gains.54 This is because states concerned about absolute gains have to make sure that if the pie is expanding, they are getting at least some portion of the increase, whereas states that worry about relative gains must pay careful attention to how the pie is divided, which complicates cooperative efforts.
Concerns about cheating also hinder cooperation. Great powers are often reluctant to enter into cooperative agreements for fear that the other side will cheat on the agreement and gain a significant advantage. This concern is especially acute in the military realm, causing a “special peril of defection,” because the nature of military weaponry allows for rapid shifts in the balance of power.55 Such a development could create a window of opportunity for the state that cheats to inflict a decisive defeat on its victim.
These barriers to cooperation notwithstanding, great powers do cooperate in a realist world. Balance-of-power logic often causes great powers to form alliances and cooperate against common enemies. The United Kingdom, France, and Russia, for example, were allies against Germany before and during World War I. States sometimes cooperate to gang up on a third state, as Germany and the Soviet Union did against Poland in 1939.56 More recently, Serbia and Croatia agreed to conquer and divide Bosnia between them, although the United States and its European allies prevented them from executing their agreement.57 Rivals as well as allies cooperate. After all, deals can be struck that roughly reflect the distribution of power and satisfy concerns about cheating. The various arms control agreements signed by the superpowers during the Cold War illustrate this point.
The bottom line, however, is that cooperation takes place in a world that is competitive at its core—one where states have powerful incentives to take advantage of other states. This point is graphically highlighted by the state of European politics in the forty years before World War I. The great powers cooperated frequently during this period, but that did not stop them from going to war on August 1, 1914.58 The United States and the Soviet Union also cooperated considerably during World War II, but that cooperation did not prevent the outbreak of the Cold War shortly after Germany and Japan were defeated. Perhaps most amazingly, there was significant economic and military cooperation between Nazi Germany and the Soviet Union during the two years before the Wehrmacht attacked the Red Army.59 No amount of cooperation can eliminate the dominating logic of security competition. Genuine peace, or a world in which states do not compete for power, is not likely as long as the state system remains anarchic.
CONCLUSION
In sum, my argument is that the structure of the international system, not the particular characteristics of individual great powers, causes them to think and act offensively and to seek hegemony.60 I do not adopt Morgenthau’s claim that states invariably behave aggressively because they have a will to power hardwired into them. Instead, I assume that the principal motive behind great-power behavior is survival. In anarchy, however, the desire to survive encourages states to behave aggressively. Nor does my theory classify states as more or less aggressive on the basis of their economic or political systems. Offensive realism makes only a handful of assumptions about great powers, and these assumptions apply equally to all great powers. Except for differences in how much power each state controls, the theory treats all states alike.
I have now laid out the logic explaining why states seek to gain as much power as possible over their rivals. I have said little, however, about the object of that pursuit: power itself. The next two chapters provide a detailed discussion of this important subject.