An Outdated Debate? Neorealism’s Limitations and the Wisdom of Classical Realism

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The purpose of this essay is to examine which of the two prominent versions of realism in International Relation’s Theory (IR) can provide us with a better account of International Politics nowadays. Both Morgenthau’s classical realism and Waltz’s neo-realism were considered as the dominant theories in the academic world of IR during their era. However, with the end of the Cold War and the emergence of the post-positivist approaches their academic dominance has been gradually turning into an existential crisis. Constructivism as the most important – and moderate – representative of this post-positivist school of thought has presented a serious challenge to both of those versions of realism. This dialectic between different approaches and schools of thought, in combination with a general challenge of the traditional theories of the field can have nothing but a positive impact on it. There is a misconception regarding our case though: A popular tendency to equalize classical realism with neo-realism as positivist and materialistic state-centric theories. Contrariwise, we will emphasize on the differences between those two, arguing that Morgenthau’s classical realism is much more broadly conceived and has several common points with constructivism. In order to do so, we will begin by underlining the epistemological and methodological gap before analyzing the different conceptualization of two notions that both of the scholars focused on: Balance of Power and Power.  The Concert of Europe and the balance it established in 1815 will be our case study for strengthening our point.

Epistemological and Methodological Gap: a Quest for Causality

The fundamental difference between classical realism and neo-realism is of epistemological – and therefore of methodological- nature: Waltz embraced a neo-positivist approach based on a scientific methodology. His neorealism was a major example of the positivist revolution that emerged in the field of social sciences during the decade of 1970 as a general quest of explaining social phenomena through objective laws, similarly to the case of the natural sciences. This revolution signaled a growing instrumental perception of knowledge (Almond & Genco, 1977).

For Waltz, knowledge should be useful, not truthful (Kurki &Wight, 2013:22). As a result, anything that cannot be measured should be excluded from the methodological process, as an obstacle to the construction of a proper theory. On the other hand, although Morgenthau has frequently been treated as a primitive positivist, there are clear indications that challenge this impression. Admittedly, this misjudged criticism is partially justifiable: After all, it was Morgenthau himself who in the first of his six principles of political realism argued that ”Politics just like society- is governed by objective laws that have their roots in human nature” (Μorgenthau, 2005:4).

However, in order to obtain a clearer picture of Morgenthau’s thought, one should also pay attention to his second most popular book, ”Scientific man vs Power Politics”, written in 1946. The close interconnection between power and knowledge was first expressed in this monumental work.  Morgenthau called all those aspiring to fully understand politics through scientific reasoning as ”true dogmatists who universalize cognitive principles of limited validity and apply them to realms not accessible to them” (Morgenthau, 1946:220) Furthermore, he argued that the ‘‘scientific man,’’ who would solve the problems of politics through the application of reason, is incapable of successfully addressing those problems’ (Barkin, 2003:331). Even the most radically post-positivist scholar could hardly disagree with such statement.

Besides his reluctant engagement with a methodological problematic, there are clear interpretative elements in his approach which will be examined below. Causal explanations based on generalizations are doubtful and some room should be left for hazardous incidents and accidental events that cannot be regularized. Morgenthau himself, quoted Blaise Pascal’s remark that “the history of the world would have been different had Cleopatra’s nose been a bit shorter” in order to underline the impossibility of regularization of social events, since regularities are not necessarily causes and this is another key contrast between the two scholars (Morgenthau, 1970:78) (Lebow, 2014).

However, theories do not deal with accidental facts rather than regularities, and that was the essence of Waltz’s positivist approach (Waltz, 1990: 27). In the criticism regarding the plethora of the omissions in his theory, Waltz argued that ”a theory can be written only by leaving out most matters that are not of practical interes.” (Waltz, 1990:31). A strong counter-argument that Morgenthau would have been in agreement with, is that a decisive difference between the social and the natural world is the role of the agency and the involvement of human actors with their own perceptions, interests and experiences. Hence, as we will examine below, the tension between the agency and the structure is a logical outcome of the aforementioned epistemological -and methological- intellectual clash.

Agency vs Structure (Reductionist and Systemic Approaches)

For reasons of simplicity, it could be argued that Morgenthau’s Inductiveness, which emphasizes the interaction of behavioral units as the direct cause of political events is opposed to Waltz’s deductiveness, where the units’ behaviour is shaped by the structure.The outcome of such an epistemological debate, regarding causality and its origins, is an absolute distinction between reductionist and systemic theories, drawn by Waltz himself (Waltz, 2011:143-178). More specifically, in his ” Man, the State and War”, Waltz distinguished between three level of analysis (Waltz, 2001). Any theory derived from the human nature and the state levels, is characterized as reductionist and considered to be inadequate to explain International Politics because of its tendency to generalise something non-calculable of which our knowledge is limited (Brown, 2009:14-16). As the main example of a reductionist theory, Waltz cited Lenin’s and Hobson’s theory of imperialism (Waltz, 2011:64-101).

Yet at the same time, a closer look to his theoretical predecessors leads to the exact same assumption of reductionism. Thus, all the main representatives of classical realism have human nature as a common starting point of analysis. In our case, Morgenthau is based on the fundamental assumption that the human nature is incomplete. On the contrary, neorealism is not derived from a theory of human nature but is exclusively focusing on the third level of analysis, the systemic one. Hence, an issue of continuity and discontinuity arises. One should question whether neorealism has actually parted company with the classical one. In fact, the debate between the agency and the structure is an extension of this major difference regarding the preferred levels of analysis and permeates and affects the phenomenally common concepts of power and balance of power. At this point, we will examine how the different conceptualizations of those two concepts reflects the epistemological difference between the two scholars.

Balance of Power

Both scholars considered balance of power as a stabilizing factor for the international order, despite its anarchic structure. It is their conceptualization of this term that differs substantially as we will examine below.

Morgenthau’s balance of power encompasses a variety of levels of social interaction, including states, groups and individuals. There is also a variety of methods of balancing in his writings (divide and rule, compensations, armaments and alliances) that prove the fluidity of the concept and, consequently, the importance of the agency in decision-making (Morgenthau, 2005:191-208).

Waltz presented the foreign policy of the states as a mechanical response to a balance of power that is based on an objective and quantitative distribution of capabilities (Waltz, 2011:214). As we already mentioned, the role of agency is being completely left out. As a result, a problematic implication occurs: Balance of power is being perceived as -an almost static-situation formed automatically (Waltz, 2011:255). Due to the anarchic structure, all states in the neorealist theory are functionally equal with similar interests. However, this absolute view has received strong criticism from some neo-classical realists who argue that neorealism is deeply pro-status quo biase (Schweller, 1996). Those scholars are actually looking back to the readings of classical realists like Morgenthau, in order to answer the explanatory deficiencies of neo-realism in the post- Cold War era (Baylis & Smith, 2007:241).

Thus Morgenthau was one of the first scholars to draw the distinction between status-quo and revisionist or imperialist states, since he perceived the concept as more of a constant process (Baylis & Smith:241). Despite defining it as ”a necessity”, the prescriptive nature of his approach is crucial and should not be ignored.  Waltz’s criticism that Morgenthau conceptualization of the balance of power is taking place variously and lacks clarity is justifiable (Waltz, 2011:251). However, despite the ambiguity of the term in Morgenthau’s writings, a major distinction should be drawn: Balancing should be conceptualized as both a principle and a practice.  It is the second meaning that is subject to statemen and decision-makers, and to what his theory owes its prescriptive character (Lebow, 2003:225-230).

In Brown’s words, Morgenthau ” is concerned to show how states ought to behave in order to create balances of power, a concern that would be meaningless if balances of power actually created themselves through some ‘necessary’ process’, while Waltz’s conceptualization of the term simply warned that anyone who ignores the systemic imperatives is doomed to be punished (Brown, 2012:40). This is the main reason why classical realism has been associated with the recent ”Practice Turn” in IR, an academically emerging approach that emphasizes the role of the agency and the notion of  practical reason, which is directly linked with Morgenthau’s ”prudence’ (Brown, 2012).

Furthermore, Morgenthau’s perspective reveals an interpretation of the Balance of power as something fluid, constructed by humans and states, subject to both human agency and their perceptions of that balance. This conceptual fluidity can be related to the constructivist approach which conceives reality to be constructed by social actors (Wendt, 1992). Being more of a prescriptive rather than a descriptive theory, classical realism encourages leaders to be prudent in order to avoid reckless behaviour that could lead to what the ancient Greeks were calling ”hubris”: The case where overconfident pride, combined with arrogance, is followed by punishment (”nemesis”) (Morgenthau, 2005:14-15). However, ”hubris” does not only occur when a great power shows greedy behaviour and decides to overextend is military influence, by disrespecting the balance of power and the international order: ”Hybris” is also related to the way (”how”) of exercising this power. That leads us to the last major differentiation between classical realism and neo-realism: The contrasting conceptualization of the notion of power itself.


Power plays a dominant role in both theories, however, the assumption of the centrality of power is mostly applicable to Waltz and the neorealists, who were the ones to reduce it to purely calculable and quantitative measures. Thus, power enjoys a much broader conceptualization in the writings of the classical realists, and especially Morgenthau’s (Jervis, 1994:856). Despite the frequent use of the centrality of power in Morgenthau’s thought and writings, he avoided to limit its use. As Thucydides first underlined power of its own sake is doomed to be ”hollow” (Lebow, 2001). Morgenthau incorporated this, since he admitted that humans would not accept power without morality. Similarly, Herz reminds us that in the ”The Purpose of American Politics” Morgenthau recognized the dangers of a cynical foreign policy based exclusively on power calculations, where the only objective becomes power for the sake of the power (Herz, 1981:184). Μorality, as a motivational force acts in combination with the quantitative  elements of national power.

A devoted critic of the Vietnam War, Morgenthau aimed to underline that despite its primary importance, power needs to be exercised carefully, with ethical concerns in mind. This broader conceptualization is also an admittance of power’s subjectiveness and the fact that power is mistakenly conceived in a narrow sense, as a demonstration of material capacities.  In contrast to the neorealists, power in classical realist thought has a much broader meaning and encompasses non-tangible components such as psychological factors (people’s morale) and more importantly, the quality of diplomacy  (Lebow, 2003:226-230). Lebow used the ”rock, scissor, paper” metaphor to prove the relational nature of power in Morgenthau’s realism, in contrast to Waltz’s both oversimplification of the character of power and his functional equalization of states (Lebow, 2003:232-233). This relational conceptualization of power is compatible with the constructivist approach since it mostly becomes a matter of perception where inter-subjectiveness prevails (Guzzini, 2013:5).

Nonetheless, this element of morality in power exercising should not be misconceived as a pro-liberal idealistic approach.  His perception of morality was state-centric, opposing to any universal account of moral values and principles (Morgenthau, 1949:207-212) In contrast to the moral absolutism of the American establishment, Morgenthau embraced a relativistic one that was translated into a consequentialist ethic: A moral foreign policy should be judged by its outcomes and not by its intentions, based on an hierarchy of choices, and more specifically, the choice of the lesser evil (Morgenthau, 2005:6).

Case Study: the Concert of Europe

The example of the ”Concert of Europe” serves as a typical historical example of a richer and wider interpretation of the concept of ”Balance of Power”. As this case demonstrated, a normative consensus can partially limit the ambitions of potential hegemons. Formed and adopted in the aftermath of the Congress of Vienna in 1815 by the winners of the Napoleonic Wars (Austria, Russia, Great Britain, Prussia), it was a system of dispute resolution that instead of only being based on checks and balances of power,  was also incorporating certain common principles and rules, that needed to be respected. Norms, principles and a common sense of justice and legitimacy served as a unifying link between heterogeneous parties, such as a constitutional monarchy (Great Britain) and an absolute one (Tsarist Russia).

Τhose states internalized these norms and followed a foreign policy not only based on estimations of crude power but also on perceptions of enmity and amity. It is this aforementioned relational conceptualization of power that both classical realists and constructivists share. As Jervis notes, for Morgenthau, ”a degree of moral consensus among nations is a prerequisite for a well-functioning international order” (Jervis, 1994:865). They all acknowledged their responsibility for ensuring perpetual stability in the continent (Lascurettes, 2017:5-8). This commitment to a certain balance was more of the result of a common culture and it did not only emerge out of the clash of competing interests as Kenneth Waltz theory suggested. Hence, those states shared common hostility towards nationalistic, revolutionary and potentially destabilizing movements across the devastated meta-Napoleonic European continent. All the members of the European Concert made several concessions for the sake of peace and stability, motivated by the shared historical memories of a destructive war (Jarrett, 2013:361).

In terms of crude power and materialism, it should be noted that the balance was rather asymmetrical, favoring tsarist Russia and Great Britain. Rather than impersonal calculations or a mechanic balancing act, it was the prudence, self-restraint and a sense of common responsibility between those two power that sustained this system. Likewise, power should be both masked and embedded, since legitimacy is a key additional element to material superiority and those two powers seemed to take that well into account (Lebow, 2008:26).

Moreover, the role of agency was of great importance in orchestrating the workings of the Concert. Personalities such as Metternich, Talleyrand performed a catalytic role in forming this system of checks and balances or ”political equilibrium”, as it has been recently characterized by modern historians (Schroeder, 1994:580). Regardless of their anachronistic and anti-liberal ideological worldview, the architects of the Concert of Europe were statemen whose prudence and sense of measure could not be denied. Hence, it was the quality of diplomacy, rather than crude material capabilities, that mattered the most during that era, providing Morgenthau’s classical realism with a powerful case study against Waltz’ purely materialistic neorealism.


Overall, this essay tried to prove that classical realism seems to provide a more comprehensive understanding of international relations, by not only encompassing the interplay between the agency and the structure but also between morality and power. By analysing Morgenthau’s classical realism with a constructive lens, the paper concluded that the internal divisions within the realist school of thought are greater than one could have first guessed. Phenomenally, the constructivist approach is completely opposed to the realist one, given the conflicting concepts of ideas and materialism, key features in those theories, respectively.  In fact, constructivism came into surface by criticizing neorealism, which arose from classical realism. Τhe main point of the constructivist argument against realism is that it is a theory incompatible with intersubjective epistemologies and methodologies. However, this broadly-shared view demonstrates a latent intention of equalising the two versions of realism. Despite its almost meta-physic attachment to nation-state, classical realism has clearly shades of constructivism and Morgenthau was the first to acknowledge the limits of knowledge. With this, we are not trying to equate the understanding of classical realism with that of constructivism rather than to emphasize its more flexible nature.

It comes as no surprise that one of the most durable arguments against neorealism is its inadequacy of addressing political change, a criticism empirically based on the end of the Cold War. Neorealism’s staticness emanates by its deliberate omission of the agency and non-tangible factors such as morality, justice and ideology from its paradigm. Self-entrapped in his cognitive realism, Waltz led his theory into a deterministic deadlock.  Despite achieving theoretical purity and clarity, it seems like it is missing the very own existential goal of social sciences: To provide us with a better understanding of the complexities of the social world. On the contrary, Morgenthau allowed greater room for inter-subjectivity and this is why his theory, half a century later, looks more resilient to the post-positivism criticism, thanks to its interpretivist elements, demonstrated by his conceptualization of power and the balance of power. This dual conceptualization proved more sufficient when tested in a specific case, 19th century’s concert of Europe. But more importantly, he knew that state leaders are not just mere prisoners of greater uncontrollable forces.

Rather than a doctrine, realism should be perceived more as an ”attitude”. Its timeless wisdom and teachings, besides a practical guide in a complex and imperfect world of contradictions can also be a theoretical guide against simplistic assumptions and aphorisms (Betts, 2015).


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Written at: King’s College London, Department of War Studies
Written for: Professor Mervyn Frost
Date written: January 2018

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