Have Waltz’s Critics Misunderstood His Theory of International Politics?

Kenneth Waltz’s Theory of International Politics (TIP) underlies his status as what Mearsheimer describes as ‘the most important international relations theorist of the past half century’ (Mearsheimer, 2009, p. 241). The impact of his novel ideas is the reason why it is requisite to properly comprehend them and their utility. It is for this reason that the first part of this essay will present some typical criticisms of Waltz’s (1) structure-centric approach and (2) his theoretical notion of anarchy, and then demonstrate some misconceptions that underlie these stances according to a Waeverian interpretation of Waltz’s intentions. In the second section, this essay will argue that the origin of these misunderstandings is the assumption that Waltz is an undivided positivist, and will highlight elements of TIP that reveal Waltz’s post-positivist tendencies. It is the disjointedness of Waltz’s positivism that will be propounded as the underlying deficiency of TIP, as opposed to the misguided criticisms referred to in the first section.

Waever argues that Waltz is ‘so consistently misinterpreted on the question of theory’ (Waever, 2009, p. 201) as debates regarding TIP assume the theory is a formal proposition which is either true or false. Whereas, Waltz establishes in chapter 1 that a theory is a simplification of reality which explains laws, rather than an accurate reflection of it (Waltz, 1979, pp. 2-8). This declaration may be considered particularly controversial, and perhaps ironic, given Waltz is a self-proclaimed neo-realist. Nevertheless, for Waltz, a theory can only be refuted if a better theory surpasses it and if it ceases to be considered useful (Waltz, 1979, p. 39). It is according to this standard that I intend to evaluate TIP.

The ontology of the international system in TIP is a structure which is composed of an organising principle, the distribution of capabilities across units, and the differentiation of units. This structure is determined by the distribution of capabilities, and anarchy; the prominent ordering principle in the international system. The latter will be explained in greater depth later in the essay. Waltz argues we can know nothing significant about the interactions between states unless we understand the context in which they take place (Waltz, 1979, p. 65), and therefore Waltz adopts a structural focus which has contributed to ‘one of the bitterest arguments within the discipline of International Relations […] between those stressing the importance of the system level as the key generator of behaviour […] and those arguing in favour of the unit level’. (Mearsheimer, 2009, p. 52)

TIP is inherently central to this structure-unit debate and faces criticism from all IR approaches; particularly from neoclassical realists for inadequately considering unit-level variables (Zakaria, 1998, p. 14). Criticisms of this type argue that TIP should have provided a more descriptive account of variables like policies, aims, and actions of states. While Waltz recognises that having more categories would make his theory more realistic, his theory is intended to be elegant, and therefore to provide general explanations and predictions, which he believes cannot be achieved at a descriptive level (Waltz, 1979, p. 65). Further to this, his theory is set out to have greater explanatory power than descriptive accuracy (Waltz, 1979, p. 115) because he believes the latter would lead to an ‘infinite proliferation of variables’ (Waltz, 1979, p. 65). Arguing in Waltz’s defence, Waever suggests that those who consider TIP to be ‘too sparse and underspecified and hence in need of elaboration’ (Waever, 2009, p. 202) are expecting a mirror image of reality. This would be an illogical expectation given Waltz establishes that explanatory power does not need to reflect reality, and so neither does his theory. Overall, as Waltz does not aspire for an all-encompassing theory based on reality, it is inapplicable to undermine TIP on the basis of it not fulfilling this criterion.

Furthermore, the demand for Waltz to emphasise unit-level variables more implies that he ignores them, which is false. Contrary to the view of Waltz as a structural determinist, Waltz explicitly writes that structural causes are only a partial explanation for international affairs (Buzan, 1992, p. 481); ‘[s]tructures shape and shove. They do not determine behaviours and outcomes’ (Waltz, 1986, p. 343). Structure is proposed to be a constraint to unit-level behaviour through socialisation and reinforcing competition between states, but it is not claimed to be a determinant causation in international politics. Waltz recognises the role of states and sees them and the structure of the system as mutually affecting through their interactions (Waltz, 1979, p. 58). TIP only isolates the structural realm from unit-level variables so it can be explored intellectually (Waltz, 1979, p. 7). Ergo, arguments that Waltz disregards unit-level variables and offers a structural determinist stance are overly simplistic.

Another controversial component of TIP is the notion of anarchy as the dominant ordering principle in the international system. Waltz proposes that anarchy results in units (sovereign states) being functionally similar because of their security-seeking behaviour. These units are separated according to their capabilities, and it is the varying distribution of capabilities which leads to different types of systems, such as bipolarity, unipolarity, and multipolarity. Waltz’s definition of anarchy in TIP is a lack of central government to enforce states’ compliance to a global directive, as opposed to another widely used definition of political disorder.

Despite this, many scholars have conflated the two and suggested that the notion of anarchy weakens the more inter-state alliances form and international agencies increase. For instance, Bull highlights how the presence of common interests, rules, and institutions among units show that there has always been an ordered international system (Bull, 2012, p. 42), suggesting that the influence these relations exert could undermine Waltz’s anarchic system. As well as this, interdependence has been proposed as an opposition to anarchy: it shows that states become compliant in order to secure their necessary ends, and therefore indicates the presence of authority in the international system. However, these examples of cooperation between states does not contradict TIP, which references the ‘wider ranging and more effective cooperation among the states of Western Europe’ (Waltz, 1979, p. 70) during the Cold War, and thereby accepts the influence of relations between states. As Milner explains, interdependence and cooperation are not opposites to anarchy, but instead they are different constituents within the international system (Milner, 2009, p. 82). In effect, cases of interdependence and cooperation cannot solely be used to sufficiently undermine TIP as they are not mutually exclusive and can co-exist in an international system.

What crucially underlies these criticisms of TIP’s focus on structure and the notion of anarchy is the misinterpreted relationship between laws and theories. Chapter 1 describes how the relations between variables are established by laws (Waltz, 1979, p. 1). For most scholars, theories are taken to be collections of related laws, meaning theories are composed of interconnected hypotheses (Waltz, 1979, p. 2). Waltz suggests that this approach can result in an infinite amount of relevant knowledge for each theory, as well as an infinite number of combinations for this information (Waltz, 1979, p. 5). Because of this, Waltz avoids this descriptive approach and instead adopts a theory which aims to explain laws (Waltz, 1979, p. 6). This notion of a theory is removed from reality, and therefore does not need to encompass unit-level variables to be a useful theory. Therefore, arguments insisting on their presence – and thus the presence of cooperation and interdependence too – are not sufficient to refute TIP. For Waltz, a scholar can discredit a law by judging its correspondence with the real world as that is a fundamental feature of its function, but this is not the case for a theory.

Instead, Waltz proposes a positivist methodological approach for testing his theory, which I will argue is incompatible with the ontology of TIP. Waltz writes that hypotheses should be inferred from the theory and then tested for their predictive capacity (Waltz, 1979, p. 69). This approach requires the structure to be differentiated from its parts so it can be treated as the independent variable. Waltz says that the way ‘political structures are generated and how they affect, and are affected by, the units of the system’ (Waltz, 1979, p. 79) should be shown by a theory. However, Humphreys remarks that Waltz’s hypothesis actually demonstrates the effect of the structure on behaviour and outcomes, while unit-level factors are absent (Humphreys, 2012, p. 398). The separation of both causal processes may allow for positivist hypotheses, but the independent variable (structure) is essentially altered in the process. The structure in TIP cannot be studied when isolated from other domains because it is continually reconstituted by the unit-level variables which Waltz excludes. This said, it must be noted that the effect of unit-level variables on the structure is limited in Waltz’s theory. This is because the structure generates the units in a one-direction causal relationship.

Waltz’s positivist approach further requires TIP to have ‘explanatory and predictive powers’ (Waltz, 1979, p. 69) to be a useful theory. TIP fulfils the expectation that a theory should indicate more important factors and specify the relations between them as the structure is isolated from other domains. But Waltz says this does not mirror reality, where ‘everything is related to everything else, and one domain cannot be separated from others’ (Waltz, 1979, p. 7). If the way structure is tested is unrealistic, then it may be fair to suppose that the resulting predictions from its tests would likewise be unrealistic. It will be impossible to determine whether false predictions are due to the realistically implausible practice of isolating the structure, or due to TIP’s theoretical notion of structure being incorrect. The nature of the mutually-affecting relationship between the structure and unit-level variables makes the isolated measurement of structural effects on unit-level variables unachievable. What’s more, Waltz concedes that TIP ‘cannot hope to predict specific outcomes’ (Waltz, 1986, pp. 343-4), because it instead describes a range of probable outcomes. Consequently, Humphreys argues that the lack of predictive capacity in TIP contradicts Waltz’s desire to adopt a positivist approach as hypotheses can no longer be inferred and tested (Humphreys, 2012, p. 402). Even if Waltz does not consider an unrealistic theory to be useless, his theory does not appear to have the necessary ‘predictive powers’ to make it useful. According to his own logic, TIP’s inability to predict events prevents it from being an effective theory.

Humphreys moreover argues that in TIP Waltz does not include the positivist methodology he advocates for in chapter 1. As he does not clearly specify the hypotheses that should be inferred from TIP, nor ‘subject them to difficult tests’, he fails to provide a positivist application of his theory (Humphreys, 2012, p. 392). Humphreys acknowledges that Waltz presents testable propositions, but insists that he does not test them in the light of historical events. Instead, Humphreys considers TIP to be a heuristic resource as Waltz’s distinction between theories and laws implies the same distinction exists between explanation and observation (Humphreys, 2012, p. 393). This means that observations cannot be tested using the same positivist methodology that is used in the making of laws. While TIP may not lead to plausible hypotheses about the specific outcomes of structural conditions, the theory can alternatively be heuristically useful as an insight into the conditions states are subjected to (Humphreys, 2012, p. 394).

TIP also redirects our attention to important elements of international politics – such as the structure of the international system – which could be obscured by other approaches, especially ones which are fixated on unit-level variables. Although Waltz potentially does not show ‘the proportionate causal weights of unit-level and of systems-level factors’ (Waltz, 1979, p. 78), he does at least present a compelling argument that the systems-level factors play a significant role. This is what Waltz would likely have aspired for, especially with regard to his notion of balance-of-power. However, it becomes difficult to ignore TIP’s failure to specifically predict events in the international political system, as is the ultimate aim of realism.


The internal inconsistencies of TIP are an area that is insufficiently addressed when evaluating Waltz’s theory, largely because scholars have become overly invested in undermining TIP with the use of contradicting evidence, and therefore have ignored the inherent difficulty in testing the theory. Potentially, the disparate understandings of TIP can be used to highlight the incongruities between Waltz’s ontology and epistemology, causing the partial quality of the theory. Waltz’s ‘organised complexity’ (Waltz, 1979, p. 12) ultimately becomes antithetical with his positivist methodology, calling to question whether abstract notions in neorealism can really be operationalised. Nevertheless, the theory may remain useful if it is regarded as having explanatory value, and if it is not surpassed by a superior theory.

This essay has demonstrated that Waltz did not intend for TIP to mirror reality, and therefore urges scholars to go beyond criticising it on this basis and instead to confront Waltz’s objective. I have also shown that confusion about the aims and means of testing theories is interlaced in debates about TIP. Finally, I have argued that Waltz’s incompatible use of a positivist approach has become a major shortcomings of TIP.


Bull, H., 2012. The Anarchical Society: A Study of Order in World Politics. Columbia University Press, New York.

Buzan, B, 1992. “Response to Kolodziej”. Contemporary Security Policy, [Online]. 13:3, 480-486. Available at: https://www.tandfonline.com/doi/abs/10.1080/01440389208404004 [Accessed 15 November 2018].

Milner, H, 2009. “The assumption of anarchy in international relations theory: a critique”. Review of International Studies, 17:1, 67-85.

Humphreys, A, 2012. “Another Waltz? Methodological Rhetoric and Practice in Theory of International Politics”. International Relations, 26:4, 389-408.

Mearsheimer, J, 2009. “Reckless States and Realism”. International Relations, 23:2, 241-256.

Waever, O, 2009. “Waltz’s Theory of Theory”. International Relations, 23:2, 201-222.

Waltz, K. N., 2010. Theory of International Politics. Waveland Pr Inc, Long Grove, IL.

Waltz, K. N., 1986. Reflections on Theory of International Politics: A Response to My Critics. Columbia University Press, New York.

Zakaria, F., 1999. From Wealth to Power: The Unusual Origins of America’s World Role. Princeton University Press, Princeton.

Written by: Jodie Bradshaw
Written at: King’s College London
Written for: Keith Smith
Date written: 05/12/18


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