Realists do share certain assumptions and are often treated as a group, but such a broad grouping obscures systematic divisions within realist theory. In this article the author argues that realism can be split into two competing branches by revealing latent divisions regarding a series of assumptions about state behavior. The first branch is Kenneth Waltz's well-known neorealist theory; a second branch, termed here "postclassical realism," has yet to be delineated as a major alternative but corresponds with a number of realist analyses that cohere with one another and are incompatible with Waltzian neorealism.
Throughout the article, the author elaborates on the similarities and differences of the two branches of realism. Overall, the major difference between these two branches the author stresses the most is that neorealist theory stresses the possibility of war while postclassical realists stress the probability of war.
Three assumptions differentiate these two branches of realism.
Most significant is whether states are conditioned by the mere possibility of conflict or, alternatively, make decisions based on the probability of aggression. Neorealism holds that the possibility of conflict shapes the actions of states, who are seen as always adopting a worst-case perspective. Postclassical realism does not assume states employ worst- case reasoning; rather states are understood as making decisions based on assess- ments of probabilities regarding security threats.
Two other differences regarding assumptions naturally follow from this possibility / probability distinction. The first related disagreement concerns the discount rate. Neorealism's emphasis on the possibility of conflict reflects the view that actors heavily discount the future, favoring short-term military preparedness over longer-term objectives when they conflict. In contrast, postclassical realism does not regard long-term objectives as always subordinate to short-term security requirements; here, states often make intertemporal trade-offs.
The second related disagreement concerns state preferences. All realists agree that military security is the state's prime responsibility and that relative military capacity ultimately depends on a state's productive base. All agree that defending the state from military threats takes first priority, but neorealists and postclassical realists disagree about the degree to which states favor immediate military preparedness over economic capacity. Within neorealism, military preparedness always trumps economic capacity if the two conflict. In postclassical realism, rational policymakers may trade off a degree of military preparedness if the potential net gains in economic capacity are substantial relative to the probability of security losses.
Neorealist Conception of State Behavior
For neorealists, states are conditioned by the mere possibility - and ability - of conflict. Neorealists regard states as adopting such a worst-case perspective for three principal reasons.
First, neorealists point to the potential costs of war as causing actors to focus on the mere possibility of conflict. Second, neorealists argue that states will ultimately focus on other state's underlying potential for aggression-as measured by material capabilities-because a state's intentions can be benign one day and malign the next. Third, neorealists maintain that rational states will focus on the possibility of conflict because defensive precautions are considered the only true assurance against aggression.
Although neorealists certainly do not maintain that international relations is a constant state of war, they nevertheless hold that the combined effects of the aforementioned three factors cause states to adopt a worst-case/possibilistic focus.
Short-term versus Longer-term
Because anarchy provides no guarantees against elimination, one could argue that states will always seek to first maximize their military security in the short term, even if doing so has less-than-ideal repercussions for the state's long-term priorities. In practice, a rational state will not necessarily discount the future in this manner, even in an anarchic system. Rather, how rational states weigh short-term military security against long-term goals depends on the strength of security competition in the international system.
Military Security versus Economic Capacity
Waltz contends that states will be concerned primarily with securing their survival. Surviving in anarchy requires both a potent military deterrent and a dynamic productive base. As a result, identifying survival as states' ultimate goal is insufficient: Will a rational state always maximize its military security, even if doing so sometimes significantly constrains its economic capacity?
Neorealists do not view economic capacity as unimportant. As Mearsheimer maintains, "states operate in both an international political environment and an international economic environment, and the former dominates the latter in cases where the two come into conflict. The reason is straightforward: the international political system is anarchic. This neorealist view favor short-term military security over longer-term military security. Why? Economic capacity ultimately provides the foundation for future military security.
Just as firms that ignore market forces will be punished, Waltz similarly argues that "a unit of the system can behave as it pleases," but "the international arena is a competitive one in which the less skillful must expect to pay the price of their ineptitude.
What Is Neorealism's Theory of Decision Making?
Since neorealism is inconsistent with the typical expected utility framework, it becomes useful to speculate as to what theory of decision making neorealism represents. Therefore, the author discusses two alternative decision making theories for neorealism.
One possibility is minimax. Actors pursuing a minimax strategy do not pursue aggregate expected utility per se, but instead choose options that minimize the maximum loss that they can suffer.
A second alternative is that neorealism is representative of prospect theory. This theory argues that actors give more weight to losses than to gains, and also that actors will often exaggerate the likelihood of rare events.
The “Postclassical Realist” Conception of State Behavior
Specifically, neorealism and classical realism share the following characteristics: (1) they have a highly static conception of international relations; (2) they rely on particular aspects of human nature-aggression for classical realists, fear for neorealists-to generate hypotheses; (3) they assume that states tend to rely primarily on the use or threat of military force to secure their objectives; and (4) they concentrate on the balance of military capabilities, with neorealists excluding and classical realists generally downplaying other international-level influences on state behavior. Postclassical realism does not subscribe to these four characteristics.
Possibility versus Probability
Waltzian neorealists place the emphasis on a single endogenous factor as affecting the likelihood of conflict: the balance of military capabilities. Aggression is seen as less likely when states balance the capabilities of potential aggressors. (Postclassical) Realist scholars point to three material factors other than the distribution of capabilities that affect the probability of conflict: technology, geography, and international economic pressures.
Short-term versus Long-term
For postclassical realism, long-term state objectives are not necessarily subordinate to short-term military security requirements; instead, actors are seen as regularly making intertemporal trade-offs. Gilpin's realist analysis provides a good contrast to Waltzian neorealism. Gilpin argues that actors do not make worst-case assumptions but are instead conditioned by the probability of conflict.
Military Security versus Economic Capacity
Gilpin's argument that all realists view states as pursuing power and security is complicated by the fact that the pursuit of power and security do not always perfectly overlap. Gilpin defines power as resources: the combined "military, economic, and technological capabilities of states." Thus, power includes - but is not restricted to - military capabilities; more specifically, power contains within it two different elements-military preparedness and economic capacity-that will sometimes be incompatible.
It is unclear whether Gilpin views states as ultimately pursuing power or security. Waltz is very clear on this question, arguing "the ultimate concern of states is not for power but for security." Yet, Mearsheimer appears to contradict Waltz on this point; Mearsheimer asserts that states ultimately "aim to maximize their relative power."
In circumstances where the pursuit of power and security do, in fact, conflict, Mearsheimer would undoubtedly end up agreeing with Waltz's view that states first seek to ensure their military security before they pursue power. For neorealists, therefore, states ultimately pursue security, not power.
Gilpin maintains that states do not have a hierarchy of objectives; Rather, Gilpin asserts that "it is the mix and trade-offs of objectives rather than their ordering that is critical to an understanding of foreign policy. Gilpin can best be understood as arguing that states do have a hierarchy of objectives, yet it is a much more flexible hierarchy than neorealists envision.
In marked contrast to neorealism, postclassical realism argues that a rational decision maker may decide to trade off military preparedness to some degree when the potential net gains in terms of enhanced economic capacity are substantial relative to the probability of security losses. States will be especially likely to make such trade-offs when their economic resources are highly constrained.
At this point the author poses a clarifying question: “Is the postclassical realist conception of power as the dominant goal of international actors distinguishable from the classical realist understanding?"
His response: “ In practice, a crucial difference exists between the two approaches concerning their view of power. Specifically, although both theories regard the international system as a competition for power, they disagree as to the form and intensity that the pursuit of power will take. Classical realism views decision makers as constantly striving to dominate others. Within classical realism, therefore, power is regarded as an end in itself: For Morgenthau, one's “lust for power would be satisfied only if the last man becamse the object of his domination”.
Postclassical realism advances a very different perspective: state decision makers do not maximize power because of an insatiable desire to dominate others; rather states pursue power because doing so allows for maximum flexibility in achieving the nation's instrumental interests. Postclassical realism holds that decision makers pursue power because it is the mechanism by which to achieve the state's overriding objectives. States are seen as seeking to enhance their share of economic resources, and hence their power, because it provides the foundation for military capacity, and furthermore because economic resources can themselves be used to influence other international actors. Whereas classical realism views decision makers as constantly striving to dominate others.
The postclassical realist assertion that states pursue power does not mean that states are seen as necessarily engaging in conquest. States can also enhance their relative share of economic resources, and hence their power, through nonmilitary means.
In summary, postclassical realism regards states as ultimately seeking to increase their share of economic resources and, hence, their power. This focus on power resembles classical realism, but postclassical realism has a very different understanding of how and why states pursue power in the international system.
Implications for Realist Theory
In this section, the author picks some cases and compare neorealist and postclasscial realist approaches to see which branch of realism explains these cases to what extent.
He begins with laying out the main assumptions of neorealism. Neorealism advances very few hypotheses about state behavior; the three principal hypotheses are: (1) balancing behavior constantly recurs, (2) states will be constrained from engaging in cooperation, and (3) states copy the advances made by rival powers (the "sameness effect").
I. Balancing Hypothesis: The Future Behavior of Germany and Japan"
The view that Germany and Japan will strengthen their militaries in order to guard against the mere possibility that the United States might act coercively clearly reflects neorealism's worst-case perspective. In this respect, neorealists maintain that Germany and Japan will not continue down the path they have taken since World War II - namely, focusing on economic capacity while avoiding large expenditures on military security. For postclassical realism, in contrast, Germany and Japan will not likely balance the United States. Even if Germany and Japan grow economically in the future, developing a military force capable of credibly deterring the economically much larger United States will continue to be very costly. Given these large economic costs, postclassical realism asserts that balancing behavior will occur only if there exists a significant probability - and not just the possibility, as neorealists argue - that the United States will use its superior military capabilities in a coercive manner.
However, the latest evidence favors postclassical realism. German defense expenditures have declined in absolute terms every year since 1990. In November 1995, the Japanese Cabinet approved a new defense plan outlining significant military spending cuts.
2. "Sameness Effect" Hypothesis: Ukraine and Nuclear Weapons
Rational states will imitate successful international technological, organizational, and other advances that have been adopted by competing powers. The most prominent case in point concerns Mearsheimer's 1993 argument that Ukraine would retain the nuclear deterrent it inherited following the breakup of the Soviet Union.
Maintaining a nuclear deterrent would have been very expensive, requiring a substantial portion of Ukraine's gross domestic product. Retaining the nuclear deterrent was costly due to high maintenance requirements.
Pursuing proliferation would also mean "prospects for aid from and trade with the West would be harmed, a setback that has security implications given the importance of economic strength to national power." In the end, the United States pledged over $900 million in direct financial assistance to Ukraine to renounce its nuclear weapons, as well as additional equipment and resources to aid Ukraine in the process of dismantling its nuclear stockpile. Russia also offered Ukraine extensive economic incentives to forgo proliferation, including forgiveness of Ukraine's multibillion dollar oil and gas debt to Russia.
Ukraine has now ceased to be a nuclear power altogether in early June 1996. This Ukrainian decision to renounce its nuclear deterrent to advance its economic capacity is a marked anomaly for neorealism.
3. Cooperation Hypothesis: Regional Trade Blocs in the Developing World
The neorealist perspective suggests that developing countries will be very unlikely to pursue cooperation, especially given that security issues are often quite salient in this region. Yet, many cooperative efforts have been initiated in the developing world in recent years, including the Southern Cone Common Market (Mercosur), the Andean Pact, the ASEAN Free Trade Agreement (AFTA), and the Central American Common Market (CACM), to name a few. Significant security issues exist within all of these organizations: (1) within the Andean Pact, Peru and Ecuador engaged in direct military hostilities in late 1994; (2) within ASEAN, defense expenditures have increased dramatically in recent years and several serious territorial disputes exist among its members, most notably over the oil-rich Spratly Islands; and (3) there is a history of strong military rivalry between Brazil and Argentina within Mercosur and also between El Salvador and Honduras in CACM. The decision of these developing countries to initiate attempts at cooperation despite these security issues significantly contradicts neorealism."
Although postclassical realism sees states as being constrained from cooperating when security issues are salient, cooperation is still regarded as being feasible if the gains in economic capacity are even more significant than the potential security risks.
The decision of these developing countries to pursue cooperation with potential rivals is incompatible with neorealism's underlying assumptions about state behavior. In contrast, for postclassical realism, such behavior is consistent with the view that rational states make trade-offs and will favor economic capacity over security concerns in situations where the potential for enhanced economic competitiveness from regional cooperation outweighs the probability of security losses.
What Should Neorealists Do Now?
Waltz engages in such a post hoc attempt to explain why many states are now emphasizing economic capacity to a greater degree vis-a-vis military security than neorealism would lead us to expect. Waltz points to the impact of nuclear weapons, arguing that they "make balancing easy to do" and enable states "to concentrate attention on their economies rather than on their military forces." By arguing in this manner that many states are currently focusing on economic capacity because nuclear weapons have made military security easier to achieve,"
Waltz's nuclear weapons argument is ultimately unsatisfactory. Even if Waltz is correct that nuclear weapons will reduce the importance of security concerns and allow states to focus more on economics, the fact remains that a great many states are emphasizing economic capacity to a greater degree than neorealism suggests despite lacking a nuclear deterrent.
Germany and Japan are focusing on economic capacity but do not possess nuclear weapons.
Finally, neorealists might respond by arguing that their theory is very parsimonious and hence cannot be expected to be empirically accurate. What use is a parsimonious theory that is wrong or that explains only a small portion of the variance? The issue, therefore, is not one of parsimony per se but of the trade-off between parsimony and explanatory power.
Specifically, postclassical realism is parsimonious in three important respects: (1) it focuses on material factors that function independently of shared social understandings and institutional characteristics; (2) it operates with a state-centric, unitary actor assumption; and (3)although not a structural theory, post-classical realism is systemic, since it focuses on international-level factors and does not examine domestic political variables.
Implications for Neonrealist Theories
Recognizing that neorealism's possibilistic focus automatically leads to a zero-sum contest with probabilistic, nonrealist theories helps to explain why, for example, neorealists have been so averse to accepting the validity of the democratic peace proposition, even as empirical evidence mounts in support of this finding. Significantly, democratic peace proponents such as Bruce Russett do not argue that war between democracies is impossible, but rather that shared democracy significantly reduces the probability of war.
The democratic peace finding is unimpressive to neorealists precisely because of their possibilistic focus. For neorealists, the relevant question is not whether shared democracy reduces the probability of conflict, but instead whether the possibility that democracies might engage in war continues to exist. Even a small number of potential outliers to the democratic peace proposition is regarded by neorealists as such a serious deficiency.
The probabilistic focus of postclassical realism is more amenable to productive discussion with nonrealist theories. Both sides are thus critiques of neorealism, albeit from different perspectives. Yet, this should not overshadow that the two sides ask similar questions and are united in the view that factors exist besides the distribution of military capabilities that cause the probability of conflict to systematically vary."