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Relative gains are (mostly) bunk

I helped to teach a course on international institutions last term. The course included an overview of the debates from the 1980s and early 1990s over multilateral agreements and the possibility of mutually beneficial cooperation between states. According to most IR textbooks, these debates established an enduring point of contention between Realist and Liberal Institutionalist perspectives – the latter focusing on absolute gains (welfare improvements) and the former on relative gains (share of power resources). I am not sure this is a very accurate summary of current debates in the discipline, I don’t think that there has been much research on relative and absolute gains in quite some time (this and this were the only articles I could find from the last decade). If my grasp on the recent history of the discipline is correct, that this is likely because the initial research programme on relative gains initiated by Mastanduno and Grieco fizzled out pretty fast when the empirical evidence proved to be mixed and inconclusive. More hardcore rational choice theorists demonstrated that the claims made about relative gains being a barrier to cooperation did not really stand up to scrutiny. Liberal Institutionalism won the argument to a large extent, but then mutated into a pretty generic rational choice institutionalism concerned with the same sort of problems of credible commitment and collective action as much mainstream economics and political science – losing touch with discipline-defining debates. So relative vs. absolute gains provides a neat way for textbook writers to distinguish between two ‘paradigms’, but it’s not a division that provides much of a guide to current research in journals like International Organization.

But the division does appear in textbooks, so it’s part of the education of many thousands of students every year. Unfortunately, the argument that if states are concerned with relative gains (share of power resources) they will forgo the benefits of cooperation is bunk and can be shown to be so very easily. In writing this up I discovered that this argument may have been made by Duncan Snidal 25 years ago, no doubt more rigorously. But the fact that its not hard for people like me who lack Prof. Snidal’s expertise in game theory to show flaws in the relative gains argument demonstrates how flimsy the argument is, even granting all the assumptions made by its Hobbist proponents.

Let’s adopt the same soft rational choice approach of many 80s and 90s IR theorists. I’m not convinced by this approach, with its contextless hypothetical examples and stereotyped, oversimplified scenarios, but it’s the ground on which proponents of the relative gains argument chose to pitch.

Suppose states A, B, C and D are states, each with a GDP of 10 trillion dollars. Let’s use GDP as a measure of material capabilities, as many neo-realists do (and with good reason). Each state therefore controls 25% of the material capabilities in the system. If (offensive) neo-realism is correct, each desires to increase their share. They are expected to forgo economic gains if it would also involve larger gains for another state, as this would lead to a reduction in their relative power. Logically, if they are rational as defined within rational choice theory, they would even accept a lower absolute income in order to have a greater share of power resources. It seems, therefore, that asymmetric trade deals that benefit some of our actors more than others would never be struck. This is not the case, however.

Let’s say A offers B a take-it-or-leave-it trade deal that will benefit A by $2trn and B by $1trn. This example follows the discussion on page 105 of Theory of International Politics where Waltz explicitly discusses an imaginary deal skewed 2:1 in favour of one state. If B is concerned with relative gains, should they take this seemingly unfair deal? Contra neo-realism, yes: it increases B’s share of power resources in the system by 0.6% and puts it ahead of C and D in terms of their power ranking. So concern with relative gains will lead towards cooperation even though the terms are unequal. Let’s say that B can offer a similar deal to C and C to D. Assuming that each deal really is a take-it-or-leave it offer in which no better alternative is available, each offer will be accepted because each time it will increase the share of power of both states involved – providing relative gains.

Finally, after this chain of deals, if D can offer A a similar asymmetric deal, will A take it? Unless A is very concerned with a very specific sort of relative gain (i.e. gains or losses relative to the most powerful in the system), then it will. The deals that A and D were not involved in reduced their share of material power, and making a deal – even if it benefits D more – will increase A’s share of power resources.

At the end of the chain of deals, each actor will have $13trn GDP and so the same 25% share of power resources that they started with. Even if they cared only about relative gains, each state has ended up better off and participating in mutually advantageous cooperation.

So under this scenario, relative gains are not a barrier to cooperation. It should be easy to see that under more realistic conditions, the same will apply. A state is unlikely to want to be left out of a multilateral trade deal that provides benefits to others, even if the deal is skewed. In his book Ruling the World  Lloyd Gruber argues that something similar to this process created the clamour to join the WTO in the 1990s – even though many states in the global South preferred its forerunner the GATT. It’s only when the number of states is very small and the distribution of benefits very skewed that we should expect relative gains to matter and to prevent cooperation.

Alternatively, if we abandon the idea that all states are threatening to each other and acknowledge that states are primarily focused on certain specific rivals  then relative gains considerations might be relevant. There’s real world evidence for this: witness concern over French arms exports to Russia in the aftermath of its annexation of the Crimea. As pointed out by my students, one of the most compelling examples of relative gains presenting a barrier to cooperation comes from international environmental negotiations, where the US seems to have been concerned to avoid any agreement that would disadvantage it relative to China.

But in the scenario that neo-realism posits, where all states are rivals, somewhat counter-intuitively relative gains considerations will no longer be relevant as a loss of relative power compared to the other contracting state may be compensated by the relative gain compared to others. 

Starting with broadly Hobbist assumptions, there are other reasons why states might avoid entering into positive-sum multilateral agreements with each other. Waltz notes that states may be concerned with the vulnerability that dependence on a potential enemy or rival might bring. States might guard their sovereignty jealously and be wary of any loss of de jure or de facto independence. But whilst the issue of relative gains might prevent cooperation in some special cases, it isn’t a general barrier to cooperation under conditions of anarchy – even if the system is characterised by competition and aggression. Glancing at the historical record, this should have been fairly obvious: transnational capitalism emerged coterminously with the turbulent European state-system.

Networked Neorealism?

The past few posts have been quite critical of Neorealism. I thought it might be interesting to say something qualified in the theory’s favour. In Networks of Nations, Zeev Maoz presents what he calls the theory of networked international politics. It hasn’t been discussed very much on IR blogs, apart from by Braumoeller over at the Monkey Cage during a discussion of systemic theory and networked vs. traditional approaches. Maoz’s theory applies familiar mechanisms drawn from existing IR theories to analyse social network patterns of interstate interaction. Drawing on Neorealism he analyses patterns of strategic interaction, Liberalism patterns of mutually beneficial self-interested interaction, Constructivism patterns of homophily and the formation of different cultural cliques, and World Systems Theory patterns of inequality and hierarchy. He also makes some novel claims about prestige and status in the network of nations, developing some original hypotheses that develop concepts within social network theory (but which also echo recent and classic discussions of status in international relations). Interestingly, he finds that each theory makes successful predictions in its own core area of competence. Combining the different mechanisms, Maoz puts forward a complex and detailed account of how the spillovers generated by cooperation amongst security-seeking states results in an increasingly complex, evolving network structure of cooperation within the international system. Democratisation within strategically interacting groups of states tends to reduce competition and accelerate the formation of cooperative relationships. Yet the system remains unequal and hierarchies of status may generate conflict.

This is only a brief summary of a dense, detailed book that examines dozens of hypotheses and a huge range of interactions at different levels of analysis within different areas of world politics. One area of focus is what Maoz calls the strategic reference group (SRG), which he refers to as the basic unit of for the analysis of national security policy within his framework. An SRG is a state’s security environment, it is made up of all the states who are likely to be perceived as threats to a state – those the state has been involved in military disputes with, those the state has been in a rivalry with, and allies of both sets of ‘enemy’ states (the friend of my enemy is my enemy). Neorealists believe that states often engage in ‘internal balancing’, arms build-ups, if they believe that they are vulnerable. The military capabilities of others are dangerous unless they are checked and negated by counterveiling power. Building up a state’s own power resources is one way a state can make itself less vulnerable, forming alliances is an alternative strategy. Do states actually behave this way? Maoz finds that yes, states will tend to build up their military capabilities if they are weak relative to their strategic reference group*. Forming alliances makes a state less likely to engage in a military build-up. So it seems that isolated states with many powerful enemies seek to increase their capabilities. States that are powerful, have powerful allies and have few enemies may feel themselves safe enough to reduce their capabilities – perhaps opting for butter instead of guns.

This at least seems to provide support for a Neorealist perspective, especially the Defensive Neorealism of Waltz, Walt and Glaser, as Maoz’s results are consistent with the hypothesis that states seek security by attempt to achieve ‘enough’ power. But there are one or two problems. First, Maoz’s definition of the strategic reference group isn’t thoroughly Neorealist. In Maoz’s analysis, states are not concerned about all other states, just specific threatening states. States have specific issues and disagreements with past enemies, strategic rivals, and their allies. Anarchy is not necessarily a war of all against all in the theory of networked international politics. Second, I’m slightly cautious about the findings as there could be other factors not included in the model that might lead to states within SRGs to experience a growth in military personal and expenditure at the same time or sequentially. Economic growth and industrialisation are likely to be regional processes and may be associated with a rise in military capabilities. Third, Maoz notes that states that are very strong compared to their SRGs are less likely to get involved in conflict. Does this support or undermine Neorealism? If Neorealists are committed to the hypothesis that unipolar global and regional inter-state systems are very unlikely to form and very unstable because they provoke counter-balancing coalitions, then this seems to undermine the theory. Fourth, although Maoz argues that these results are robust and in line with Neorealist expectations, he notes that they don’t have a great deal of predictive power. So Neorealist theories don’t explain all that much how states respond to potential threats – perhaps (as Maoz suggests) because states have many foreign policy tools available to them apart from military build-ups and alliance formation.

Maoz examines many other processes within the global inter-state system in further detail, again finding that some Neorealist claims are borne out. But so are the claims of other theories, such as democratic peace theory. Even on a charitable interpretation of patterns of conflict and cooperation, Neorealism provides an incomplete account of the phenomena that it was created to make sense of.

Maoz’s Networks of Nations is a fascinating application of familiar theoretical frameworks to a host of levels of analysis within the international system – social network analysis seems to offer a veritable smorgasbord of possible levels of analysis for international relations scholarship. Focusing on indirect as well as direct interactions between states offers a very powerful set of tools for scholars looking for behavioural patterns in world politics. It would be especially interesting to see a network analysis of other middle-range theories in IR – is for example territorial peace and conflict a network phenomena? In my view such research would help us think creatively and rigorously about the nature of international systems and move past exhausted theories.

*I think that there is a mistake on page 143, which states that the variable State/SRG capability imbalance is generated by ‘subtract[ing] a state’s military capabilities from the sum of the military capabilities of its SRG members’. The name of the variable, the discussion in the text, and the operationalisation of the variable in the case where a state has no SRG all suggest that this is a typo and that the actual operationalisation is the state’s military capabilities less the sum of the capabilities of the states in its SRG. This operationalisation is consistent with Maoz’s interpretation of the negative coefficient for the variable in regression model for military build-ups: ‘As the difference between the capabilities of the focal state and the aggregate capabilities of its SRG increases, the extent of the absolute and rate-of-change in the state’s capabilities declines’. In other words, states with large capabilities and a weak set of states in their SRG (i.e. a positive State/SRG capability imbalance) are likely to reduce their military capabilities.

Leaving exhausted theories behind

Two years ago prominent Neorealist authors Mearsheimer and Walt lamented the current inattention to grand theory in IR as an academic field (which they also summarised over at Duck of Minerva). They argued that ‘simplistic hypothesis testing’ had replaced inquiry into the fundamental features of world politics and the debate among rival intellectual frameworks seeking to make sense of international relations. There probably is too much ‘simplistic hypothesis testing’ in IR, the use of positivist methods to answer micro-questions that no-one has every actually cared about abounds in major journals. But Mearsheimer and Walt’s critique was odd and misdirected in lots of respects, as others noted at the time it was published. Notably, M & W are dismissive of any non-positivist approach such as critical theory and feminism – yet their commitment to positivism hardly sits well with their aversion to ‘normal science’.

I’ve got time for Stephen Walt as a theorist, his version of Neorealism is flexible and non-dogmatic. His analysis in his blog is measured and rejects nationalistic claims about US exceptionalism. But along with Mearsheimer, his criticism of ‘simplistic hypothesis testing’ reads like rearguard action in support of a version of Realism that just doesn’t convince any more, doesn’t provide any useful leads for empirical research and doesn’t warrant any further theoretical refinement.

The example that they use to illustrate ‘simplistic hypothesis testing’ is telling, as it does little to support their case. Research by conflict theorists on strategic rivalries, they claim, produced:

an expanding set of empirical findings but did not produce a broader synthesis or a general explanation of the various positive and negative results. Instead, we get generalizations of the following sort: ‘Dyads that contend in territorial disputes have a greater probability of going to war than is expected by chance,’ or ‘[Enduring] rivals have a greater probability of going to war than other dyads’ (Vasquez and Leskiw, 2001: 308–309). But we still have little idea why.

Glossed over here is the issue that these findings have been interpreted by scholars as running directly against the default assumptions of Neorealism! Conflict theorists in the steps to war tradition argue that war does not arise out of the general jockeying for power among states, the whirl and dance of military coalitions that states create and dissolve as they each seek to advance their own power or security at the expense of any and all others. Instead, conflict originates in specific issues over which pairs of states disagree – most often territorial issues – and self-reinforcing, reciprocated patterns of power-political behavior between such pairs of states. It is completely false to suggest that the claims in the strategic rivalries literature are atomic, atheoretical hypotheses – they are part of a well-established, elaborate research project set out most fully in Vasquez’s The War Puzzle. It’s also false to suggest that no attempts have been made to explain why territory is especially likely to generate conflict or why strategic/enduring rivals account for so much conflict in modern international history. Vasquez’s original arguments suggested links between the psychology of territoriality and aggression, he and others later emphasised the role of hardliners and the formation of pro-war coalitions within states in sustaining rivalries, others still emphasise the socially constructed aspects of territory and rivalry. The arguments and empirics presented by the steps to war approach might still fail to convince, but it makes no sense to claim that it is not a theoretically-informed research programme that attempts to contribute to our knowledge of fundamentally important features of the international system.
M & W’s example is badly chosen and interpreted uncharitably and misleadingly. On the other hand, Vasquez’s criticism of Neorealism as a research programme, made in 1997, still stands up:

The field hardly needs realism to tell it that states will oppose threats to themselves (if they can) or that revisionist states will seize opportunities to gain re-wards (especially if the risks are low).

Once again, Neorealism offers little more than the banal observation that international politics is a rough-and-tumble world and that states pursue their interests – if we define interests broadly enough to include just about any possible goal that a state might feasibly pursue. Walt has offered some well-judged observations about contemporary international politics, but these are often made in spite of Neorealism – indeed as corrections to the baseline Neorealist model developed by Waltz. The discipline of IR doesn’t need Waltzian Neorealism as a grand theory, certainly not to the exclusion of critical theory, or middle-range research programmes such as steps to war, or the much more convincing rival systemic theories that despite M & W’s protests are actually out there.

Changing My Mind II: The Third Image is Where the Action is At

Yesterday I talked about how I’ve changed my mind about Neo-Realism, going back and forth on Waltz’s Theory of International Politics. The key issues in assessing Waltz’s opus is, I think, not the question of whether Waltz characterises this or that feature of the international system, but whether Waltz identifies a mechanism that emerges from the interaction of states that pushes the international system towards an equilibrium point, irrelevant of influences from other spheres of the social world.

I think that this project has not been successful and that there are significant implications for IR theory in general. Waltz wanted to put forward a ‘Third Image’ theory that would explain patterns of international outcomes in terms of international processes alone. If he had accomplished this, IR theory could be freestanding and IR could be studied independently of politics, economics and sociology more broadly. This notion was attacked by scholars such as Robert Cox quite early on, and in the long run they have had the better of this argument.

I am also very sceptical of alternative efforts at establishing a free-standing ‘Third Image’ theory of international relations, such as that advanced by Alexander Wendt. In Social Theory of International Politics he attempts to offer a Constructivist Third Image theory in which states establish their identity in relation to each other. One again, international relations is conceived of as a separate domain of social activity, Wendt intentionally brackets domestic political processes (1999: 11, 13). States are theorised as corporate actors who negotiate the norms of international conduct with each other as if they were individual persons. Wendt even introduced a teleological argument that does the same job as Waltz’s claims about general equilibrium, flattening the importance of particular actions of states over the long-run. Despite Wendt’s status in the discipline, the actual substantive theory offered by Wendt has been taken up by surprisingly few scholars – perhaps because it introduces a whole host of controversial Constructivist commitments without moving very far from Waltz’s framework.

So the prospects for a self-standing Third Image theory of international relations do not seem that great and much high theory in international relations has been misguided. I don’t think that this need cause to much concern, however, as there still might be important processes that operate at the system level, especially once we recognise that these processes are likely to shape and be shaped by other social, economic and political processes.

But a logical consequence of this is that sharp distinction between foreign policy and international relations cannot be maintained. If states do not adjust their policies to external circumstances rapidly  and the system does not exhibit strong equifinality, then the foreign policy of states will matter quite a lot as it will push the system in all sorts of different directions. This is what Braumoeller argues in Great Powers and the International System, in which he develops a partial rather than general equilibrium theory of international politics. Alternatively if the tendency in the international system is to concentration of power and not balance and the structure of the international system is conceived of as including institutional frameworks and ideology as well as physical resources, then the international system might evolve under the leadership of a series of hegemons. This is the argument put forward by scholars working in the tradition of Arrighi and Modelski (both now deceased, sadly).

These approaches provide systemic theories that employ a notion of the system that is broader than the relations between states, narrowly conceived. They are theories of world politics, not just IR, as they try to incorporate domestic politics and transnational processes into their frameworks. Their notions of structure are broader than the spare accounts of Wendt and Waltz. We also seem to have brought politics back into the picture, which is missing from the classic Third Image theories (Liberal Institutionalist approaches are just as guilty on this score). This is the direction that I believe we should head in: developing theories of world politics by bridging foreign policy and IR, analysing the international dimensions of domestic political change and identifying the reciprocal effect of structure and agency on one another. This might seem ambitious, but a massive amount of knowledge about the historical development of world politics has accumulated and, if we take the Third Image blinkers off, there is no reason we cannot make use of it.

Changing My Mind I: Neo-Realism

As noted in my post a few days ago, I’m going to emulate Stephen Walt with a short series of posts about how I’ve changed my mind on some major issues in international relations since I first starting studying the subject way back at the beginning of the War on Terror. One of those issues is the status of the theoretical perspective that Walt is a major contributor to: Neo-Realism (or Structural Realism). The theory is still described as the orthodoxy within IR, even though that hasn’t been the case for a long while. Nonetheless, as Wohlforth has argued, it’s still an important foil for rival theories. Indeed, criticising the central Neo-Realist text, Waltz’s Theory of International Politics, is one of the few things that gives the discipline any kind of coherence.

Nearly everything I read on IR theory as an undergraduate and MA student was an attempt to refine or overcome the framework set out by Waltz. When introduced to the theory, I agreed with the criticisms that Waltz’s approach was fatalistic, mechanical and ideological: providing a set of rationalisations for callous and cynical foreign policy. But once I started to read ToIP for myself I realised that it wasn’t philosophically naive at all, but the product of serious reflection on the nature of social scientific theory. Although I disagreed with the substantive claims of the theory, I respected it as an intellectual achievement. When I started my doctoral research, I was persuaded by the more positive reappraisals offered by scholars such as Nexon and Goddard as well as PT Jackson, Richard Little and even Justin Rosenberg.

Nonetheless, I’ve cooled on the theory as a starting point for theorising. Waltz’s framework was an intellectually rigorous attempt to define international politics as a separate sphere of social activity governed by its own laws. The problem is that huge amounts of evidence and compelling theory has accumulated that international politics is closely, perhaps inseparably intertwined with domestic politics and the world economy. Waltz attempted to distinguish between theories of foreign policy, which explain particular courses of action, from theories of international politics, which identify recurrent patterns of behaviour. But this gambit depends on the identification of an equilibrium that the system tends towards: if the system has a natural rest point to which it will always tend, we don’t need to be too concerned with how it will get there.

The problem with this argument is that Neo-Realism has had huge difficulty in identifying this equilibrium point. The claim that the international system tends naturally towards a balance of power has proven difficult to defend theoretically and empirically. Scholars have tried to patch up the problems with BoP theory and with Waltz’s ambiguous statements about what Neo-Realism actually expects to occur in international poltiics, but the difficulties have mounted up much more rapidly. Wohlforth, a major proponent of Neo-Realism, has even argued that Robert Gilpin’s argument that concentration of power is the norm would have made a more compelling starting point for Neo-Realist theory – but Gilpin never attempted to separate international relations from politics and economics like Waltz did. Waltz made a compelling case for systemic theory and for a focus on structure, but I think the discipline has absorbed what it needs from Neo-Realism and can move on. The attempt to establish a general equilibrium theory that would enable us to understand any international interaction in terms of the system-wide balance of power has not been successful.

Blogosphere Round-up II: Kenneth Waltz, Rational Choice, People Power and Self-Promotion

I’ve read a series of things recently that made me want to write something, but that probably wouldn’t support a full blog post. So here’s another round of discussions going on that are in some way relevant to past posts on this blog.

  • via Martin Hewson/Breviosity, here’s an article by Ian Clarke on the significance of Waltz contribution to international relations theory. I agree with the opinion expressed over at Breviosity that, although Waltz gave realism a second lease of life, debates in IR might have actually turned out fairly similar even without Waltz’s Theory of International Politics. I think, however, that ToIP has helped tie the discipline together by providing different theoretical perspectives (as well as some atheoretical perspectives) a common foil (I think Wohlforth has argued something similar).
  • There’s been a very interesting debate over on the Duck of Minerva about rational choice theory and whether it conceives of actors as autonomous from their environments (1, 2, 3, 4, 5). This debate is of especially interest because I’m reading a book by Jon Elster (philosopher of science and advocate turned critic of rational choice theory) that is specifically concerned with methodological individualism and the way in which we different kinds of relations amongst actors should be characterised. I might write a short post on this topic soon. Over on the comments thread at Howl at Pluto I took issue with Jackson’s Kantian-Weberian characterisation of moral decision making during the course of this debate. From memory and from the bits and pieces I’ve read more recently, I don’t think contemporary political philosophers/philosophers of action draw such a sharp distinction between ‘value-rational’ and instrumental action.
  • The wave of popular protests against the world continues to rumble on, prompting attempts to explain the connections between the events as well as derision of some of those attempts (I’ve commented on the Blood and Treasure post). In the course of reading round this topic, I’ve discovered the really rather good Political Violence @ A Glance blog  (which provides interesting analysis of some of the facets of protests in Brazil and Turkey).
  • Via a Tweet by Pablo K, I discovered that my article in Millennium and the rest of the pretty damn interesting special edition on ‘Materialism and World Politics’ is currently open access. It’s never been easier or cheaper to read my thoughts on the connection between global inequality, labour markets and the democratic peace!

Farewell to Kenneth Waltz


Yesterday via The Duck I learnt that Kenneth Waltz has passed away. Waltz is a central figure in international relations theory, Theory of International Politics can be considered the founding text of the contemporary discipline. There are some tributes (including my own) and a pair of anecdotes/excerpts that illustrate Waltz’s independence of mind and his knack for pithy insight.

I remember sitting down to read Theory of International Politics as a Masters student, already broadly but superficially familiar with neo-realism from an introductory undergraduate course. At this point I was naively, arrogantly confident that theorists I didn’t agree with could easily be pigeon-holed and dismissed as either dogmatic methodological individualists, naive empiricists, or sophists playing word-games. Waltz fell into none of these categories: Theory of Politics is a rigorous, philosophically sophisticated framework for the analysis of international relations. Striving to establish a parsimonious account of international relations as a bounded realm governed by its own structural laws, it draws on microeconomics, Durkheim and Newtonian physics. Like most everyone else in the discipline, I also believe that it is wrong on many of its major points. But everyone who has attempted to think systematically and rigorously about the international system subsequent to Waltz has had no other option but to engage with him. It’s for this reason that even radical critics such as Rosenberg have acknowledged their debts to Theory of Politics.

In engaging with Waltz, scholars of international relations have subjected Theory of International Politics to innumerable criticisms. Many of these criticisms, which often consist of pointing out that Waltz’s theory ignores X or Y, were misconceived. The most convincing interpretation of Theory of Politics, that of Goddard and Nexon, sees Waltz as putting forward a ‘spare account of the dynamics of anarchy’ within a bounded sphere of international politics. This account is offered by Waltz, not as a description of the world as it actually is, but as an idealised framework to enable explanation of particular events against a baseline of expectations. The more serious criticisms, therefore, were those that accused neo-realists of sleight of hand by equivocating between methodological and substantive claims (i.e. outlining a model and then treating this as an accurate description of reality). In addition, arguments from social theorists and historical sociologists have put the validity of this sort of approach into question. Mann, for example, argues that it is impossible to convincingly separate bounded spheres of social life from one another and identify autonomous ‘system-logics’ of such spheres.

Nonetheless, much of the most interesting and insightful contributions to international relations theory – such as those of Cox, Buzan, Little, Rosenberg, Spruyt and Ruggie – have been direct responses to Waltz’s opus. The engagement with Waltz is one of the few things that gives International Relations any kind of coherence as an academic discipline. It is impossible to understand contemporary International Relations without a familiarity with Waltz’s work and for that reason he is sure to be studied for a long time to come.