Balance of Power Theory in Today’s International System

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“Balance of power theory grew out of many centuries of multipolarity and a few decades of bipolarity. Today the world is characterized by unprecedented unipolarity. Balance of power theory, therefore, cannot provide guidance for the world we are in.”

In responding to this statement, the essay will first discuss the logical fallacy inherent in its argument: though the balance of power theory (BOP)[1] emerged concurrent to certain types of power configuration in world politics—multipolarity and bipolarity in this case—it does not follow that it was these types of configuration per se that gave rise to the theory itself. Multipolarity and bipolarity can and should be considered, themselves, as manifestations of the underlying logic of the international system, which the BOP theory also embodies. This logic of relative positionality of states in an anarchic system, as this essay will argue, has not fundamentally changed since the emergence of BOP theory. This leads to the second empirical problem with the statement. On the one hand, a de facto unipolarity characterized by American hegemony has been around for much longer than the end of the Cold War. On the other hand, the current economic and political status of China places it in a pseudo-superpower position vis-à-vis the United States. Both of these mean that the degree of unipolarity that we observe today relative to the bipolarity of the Cold War is, if any, weak. Therefore, much of BOP’s relevance in the bipolar world will continue to be in today’s international system.

The BOP Theory: Core Assumptions and the (ir)Relevance of Polarity

We should first understand the logic that gave rise to the BOP theory. Two assumptions are of central relevance. First, the international system is considered to be anarchic, with no system-wide authority being formally enforced on its agents (Waltz 1979, 88). Because of this “self-help” nature of the system, states do not have a world government to resort to in a situation of danger, but they can only try to increase their capabilities relative to one another through either internal efforts of self-strengthening, or external efforts of alignment and realignment with other states (Waltz 1979, 118). Second, states are the principle actors in the international system, as they “set the terms of the intercourse” (Waltz 1979, 96), monopolize the “legitimate use of force” (Waltz 1979, 104) within their territories, and generally conduct foreign policy in a “single voice” (Waltz 1959, 178-179). Hence states are also considered to be unitary actors in the international system. This latter assumption is important because if non-state or transnational actors are powerful enough to challenge state actors, power configuration in the world may no longer be considered in terms of polarity but, instead, in terms of the number of layers of policy “networks”[2]. This essay bases its argument on these two core assumptions about the international system as well because they have been widely accepted not only in realism and neorealism but also in neoliberal institutionalism (Keohane 1984, etc.) and, to some degree, in constructivism (Wendt 1999, etc.) as well. Thus, they are not derivative from exclusively realist or neorealist beliefs such as relative power maximization.

With this in mind, the essay will now discuss why polarity is neither sufficient nor necessary to explain the balance of power. The question of sufficiency can be answered with respect to why balance of power does not always occur even in a multipolar or bipolar world, and that of necessity with respect to why balance of power can still occur even with unipolarity. According to Waltz, balance of power occurs when, given “two coalitions” formed in the international system, secondary states, if free to choose, will side with the weaker, so as to avoid being threatened by the stronger side (Waltz 1979, 127). This condition has led some to question the validity of BOP in a unipolar world, since two or more states need to coexist in the system in order for the theory to hold (Waltz 1979, 118).

However, as this essay mentions, once we accept the two core assumptions (that of anarchy and that of states being principle actors), this condition is not necessary for BOP to be relevant. The balance of power, as Waltz suggests, is a “result” – an outcome variable that reflects the causal effect of the explanatory variables which are, in his theory, anarchy and distribution of power in the international system. This tension within Waltz’s own argument has indeed invited criticism that his version of the BOP theory is essentially attempting to explain one dependent variable (the occurrence of balance of power) with another (polarity) (Lebow, 27). To sidestep this potential loophole, therefore, we need to assess the relevance of BOP by examining whether the same structural constraints that engender balancing in the multipolar or bipolar systems are also present in a unipolar world.

If the balance of power could not be directly deduced from system polarity, what then would predict its occurrence? To answer this question will require us to go back to the two core assumptions and see what explanatory variables can be derived from these assumptions that will have some observable implications with regard to balancing. The likelihood of balance of power is, therefore, a function of these variables which, as this essay will show, boil down to 1) intention, notably the intention or the perceived intention of the major powers in the system, 2) preference of the states, particularly that between absolute and relative gains, and 3) contingency, often related to the availability of new information in a given situation, which may exogenously change the first two variables. Most importantly, none of the three is conditional upon a certain type of polarity to be effectual.

Three Explanatory Variables for Predicting Balancing: Intention, Preference, Contingency

The intention, or the perceived intention of a major power, determines whether balancing will be preferred by secondary states over other options such as bandwagoning. We can think of this in terms both why smaller states sometimes succumb to the sphere of the strongest power in the system and why they sometimes stay away from it, or challenge it by joining the second biggest power if there were one. In his analysis of the conditions for cooperation under the security dilemma, Robert Jervis shows that when there is pervasive offensive advantage and indistinguishability between offense and defense (the “worst case” scenario), security dilemma between states can be so acute that it can virtually squeeze out the “fluidity” necessary for any balance of power to occur (Jervis 1978, 186-189). By incurring incorrect “inferences”, offensive advantage and offense-defense indistinguishability ultimately serve to alter the perceived intention of the adversary as being aggressive or non-aggressive (Jervis 1978, 201). This will then dictate the smaller states’ decision to whether balance the move. If, however, the major power is perceived to have not only a non-aggressive intention, but also a benign intention of providing certain public goods, smaller states may choose to free ride on these benefits while submitting to the major power’s sphere of influence in return; an outcome of so-called “hegemonic stability” may then ensue (Keohane 1984, 12). Thus along the dimension of perceived intention, balance of power occurs when states have reservations about the major power or the hegemon’s intention but not to the extent that a precipitation to war is so imminent as to render balancing infeasible.

Second, balance of power is closely related to the states’ preference for relative versus absolute gains. From an offensive realist point of view, John Mearsheimer contends that states concerned with balance of power must think in terms of relative rather than absolute gain – that is, their military advantage over others regardless of how much capability they each have. The underlying logic here is at once intuitive—given a self-help system and self-interested states, “the greater military advantage one state has…the more secure it is” (Mearsheimer 1994-95, 11-12)—and problematic since the auxiliary assumption that every state would then always prefer to have maximum military power in the system (Mearsheimer 1994-95, 12) is practically meaningless. Similarly, Joseph Grieco points out that with the ever present possibility of war in an anarchic system, states may not cooperate even with their allies because survival is guaranteed only with a “proportionate advantage” (Grieco in Baldwin ed., 127-130). The concern for relative gain predicts that states will prefer balance of power over collective security because the latter requires that states trust one another enough to completely forgo relative gain through unilateral disarmament, which is inherently at odds with the idea of having a positional advantage for self-defense (Mearsheimer 1994-95, 36).

Meanwhile, the neoliberal institutionalist cooperation theory essentially presumes the pursuit of absolute gain over relative gain for states to achieve cooperation (Keohane 1984, 68). On a broader scale, therefore, the pursuit of relative gain would undercut international cooperation in general, in both high and low politics. It is safe to say that in practice, states are concerned with both relative and absolute gains to different degrees under different circumstances. Scholars like Duncan Snidal and Robert Axelrod have rigorously demonstrated the complexity of situations in which these two competing interests dynamically interact and change over time (see for example Snidal in Baldwin ed. and Axelrod 1984, Chapter 2). In general, though, a prevalent preference for relative gains and, more specifically, military positionality among states increases the likelihood of balancing relative to collective security. If states tend to favor absolute gains instead, we are more likely to see phenomena such as deep international institutions and pluralist security communities.

But even if there existed a malign hegemon that other states wanted to balance against, and the states all pursued relative gains, balance of power would still be conditional. That is, even with the aforementioned systemic constraints, balance of power is not a given without knowing the specific contingency factors unique to each situation. One additional implication of an anarchic system is pervasive uncertainty resulting from the scarcity of information, since all states have an incentive to misrepresent in order to further their positionality in event of war (Fearon 1998, 274). This explains why, perhaps in a paradoxical way, historically even in periods of multipolarity and bipolarity characterized by intense suspicion and tension, balancing did not happen as often as BOP would predict. The crux is the unexpected availability of new information which leads to a change in the course of action by altering preexisting beliefs and preferences. The European states’ collective decision to buttress the rising challenger Prussia in the 1800s despite the latter’s clear expansionist tendency shows that neither intention nor preference can be taken as a given, but both are subject to circumstantial construction (Goddard, 119).

In times of crisis, this constructing effect may be especially strong. Such characterized the interwar period and resulted in a significant lag in the European states’ learning which may have otherwise incurred greater balance against the revisionist Germany (Jervis 1978, 184). Still caught up in a spirit of collective security from the first war, these states were too “hot-headed” to switch to the phlegmatic behavior of balancing (Weisiger, lecture). This, however, had less to do with their perception of Germany or their pursuit of relative/absolute gains than with the transformational effect of the trauma of World War I. In short, the more rapid and unpredictable is the flux of information in a given situation, the less likely that the balance of power contingent on existing beliefs and preferences will occur as predicted.

The Fall of USSR, the Rise of China, and Empirical Implications for the BOP Theory

Having shown that BOP has less to do with polarity than with intention of aggression, preference for relative gains, and circumstantial factors in an anarchic world, this essay will now show why our current system, characterized by American hegemony, is not so much different from the preceding ones. Doing so will not only address the necessity question mentioned earlier, but also show that even if we accept the premise that BOP is less applicable to unipolarity than to multipolarity and bipolarity, this hardly affects BOP’s relevance to today’s world.

Though BOP gained much leverage during the Cold War, which is considered a textbook case of bipolarity, a closer look at Waltz’s discussion of American dominance at the time reveals what really resembles a picture of American hegemony rather than bipolarity (Waltz 1979, 146-160). Most important, however, is the fact that concurrent to this widening gap between the U.S. and the USSR, a corresponding increase in the balance of power against the U.S. did not occur. Rather, we saw the opposite happen where Soviet satellite states started drifting away one after another. This greatly undermines BOP’s explanatory power even for bipolarity. Richard Lebow’s succinct summary of the years leading to the Soviet collapse illustrates that not only did the USSR productivity remain vastly inferior to that of the U.S., but also that its military (nuclear) capabilities never reached the level as to be a real challenger to the U.S. Hence, the actual period of strict bipolarity during the Cold War is much shorter than is conventionally believed (Lebow, 28-31). It is debatable as to what extent the Soviet “anomaly” was primarily the result of perception, preference, or contingency (such as that discussed in Risse, 26), but major discordances between the balance of power and polarity lend further support to this essay’s argument that BOP is not determined by polarity itself, but by variables inherent in the international system, which may or may not lead to a concurrence of balance of power and certain types of polarity.

The demarcation between the bipolar Cold War system and the unipolar post-Cold War system is, therefore, fuzzy at best. This has been further complicated by China’s rise in the most recent decades. To put things in perspective: at the peak of the Cold War, the U.S. enjoyed a GDP of $5,200 billion (USD)—about twice of that of the USSR ($2,700 billion). As of last year, it was $16,000—also about twice of that of China’s ($8,200 billion).[3] If we were to measure superpower status by nuclear capability (which many scholars use to pinpoint the start of Cold War), the picture is even more ambiguous, with as many as nine states currently having nuclear weapons, including North Korea.[4]

Rather than questioning American hegemony today, which this paper does not intend to do, these facts simply serve to remind us of the continuity rather than discreteness of the recent stages of polarity. Because of this, the supposed unipolarity as of present has little bearing on the validity of the BOP theory in explaining state behavior. Hans Morgenthau reaffirms the balance of power as a “perennial element” in human history, regardless of the “contemporary conditions” that the international system operates under (Morgenthau, 9-10). The essence of the BOP theory cannot be reduced to the occurrence of balance of power. With the logic of anarchy and principality of state actors largely unchanged, we can, therefore, imagine a situation of balancing against the U.S. even in a unipolar system—if the U.S. is no longer perceived as a benign hegemon and if states are more concerned with their military disadvantage as a result, especially when a combination of situational factors and diplomatic efforts further facilitates such a change in perception and preference.


Axelrod, Robert, The Evolution of Cooperation, 1984.

Fearon, James, “Bargaining, Enforcement, and International Cooperation,” International Organization 52:2, 1998.

Goddard, Stacie, “When Right Makes Might: How Prussia Overturned the European Balance of Power,” International Security 33:3, 2008-2009.

Grieco, Joseph, “Anarchy and the Limits of Cooperation: A Realist Critique of the Newest Liberal Institutionalism” in David Baldwin ed., Neorealism and Neoliberalism: The Contemporary Debate, 1993.

Jervis, Robert, “Cooperation under the Security Dilemma,” World Politics 30:2, 1978.

Keohane, Robert, After Hegemony: Cooperation and Discord in the World Political Economy, 1984.

Lebow, Richard Ned, “The Long Peace, the End of the Cold War, and the Failure of Realism,” in Richard Ned Lebow and Thomas Risse-Kappen eds., International Relations Theory and the End of the Cold War, 1995.

Mearsheimer, John, “The False Promise of International Institutions,” International Security 19:3, 1994-1995.

Morgenthau, Hans, Politics among Nations: The Struggle for Power and Peace, 1967.

Risse, Thomas, “‘Let’s Argue!’: Communicative Action in World Politics,” International Organization, 54:1, 2000.

Snidal, Duncan, “Relative Gains and the Pattern of International Cooperation” in David Baldwin ed., Neorealism and Neoliberalism: The Contemporary Debate, 1993.

Waltz, Kenneth, Theory of International Politics, 1979.

Waltz, Kenneth, Man, the State, and War: A Theoretical Analysis, 1959.

Wendt, Alexander, Social Theory of International Politics, 1999.

“The World Factbook,” Central Intelligence Agency.

[1] I will use the acronym “BOP” to refer to the theory of balance of power, and “balance of power” to refer to the actual phenomenon of balance of power.

[2] This term is directly borrowed from the title of Networked Politics by Miles Kahler, but numerous works have alluded to the same concept, such as those by Kathryn Sikkink, Martha Finnemore and Anne-Marie Slaughter, to name a few.

[3] The World Factbook, Central Intelligence Agency.

[4] Ibid.

Written by: Meicen Sun
Written at: University of Pennsylvania
Written for: Mark Katz
Date written: October 2013

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