The ‘Great Debates’ in international relations theory

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International relations in the most basic sense have existed since neighbouring tribes started throwing rocks at, or trading with, each other. From the Peloponnesian War, through European poleis to ultimately nation states, Realist trends can be observed before the term existed. Likewise the evolution of Liberalist thinking, from the Enlightenment onwards, expressed itself in calls for a better, more cooperative world before finding practical application – if little success – after The Great War. It was following this conflict that the discipline of International Relations (IR) emerged in 1919. Like any science, theory was IR’s foundation in how it defined itself and viewed the world it attempted to explain, and when contradictory theories emerged clashes inevitably followed. These disputes throughout IR’s short history have come to be known as ‘The Great Debates’, and though disputed it is generally felt there have been four, namely ‘Realism/Liberalism’, ‘Traditionalism/Behaviouralism’, ‘Neorealism/Neoliberalism’ and the most recent ‘Rationalism/Reflectivism’. All have had an effect on IR theory, some greater than others, but each merit analysis of their respective impacts. First we shall briefly explore the historical development of IR theory then critically assess each Debate before concluding.

Historical Context

Regarding Realism, throughout history various actors have followed the path of self-interest, power projection and conflict. Thucydides chronicled Athens’ zero-sum war with Sparta from 431-404BC, while centuries later Machiavelli noted that ‘‘the first way to win a state is to be skilled in the art of war’’ (1999, p. 47). Thomas Hobbes’ Leviathan, suggested that a hegemonic power was required to impose order, ensuring man’s survival and security and protecting him from his nature, that of war and power (Bull 1981, p. 190). Leviathan was published in 1651, not long after the 1648 Peace of Westphalia which, conveniently or not, is often regarded as creating the nation state system, an international environment that was conductive to the kinds of power-plays Realists subscribed to. There are various facets to Realism, yet its core tenets remain an advocacy of the primacy of the sovereign nation state, which must rely on its own power accumulation to maintain its security and therefore survival.

Cosmopolitanism was a moral and socio-political philosophy of Ancient Greece, essentially maintaining that all people, regardless of difference, were members of a community. While not identical, similar Liberalist sentiments were advanced by Enlightenment writers. Many advocated the interests of the individual and called for states to be conductive to these, such as John Locke’s espousal of inalienable natural rights and the Utilitarianism advocated by Jeremy Bentham (Viotti and Kauppi 1999, p. 201), who also wrote much on judicial reform and international law. Immanuel Kant believed that ‘‘a cosmopolitan whole, i.e. a system of all states’’ (Höffe 2006, p. 136) could eventually establish a perpetual peace. These are very basic summations of their proposals, and there were differences between them, yet this highlights a gradual evolution in proto-Liberalist thinking, with these principles and others coalescing into advocating cooperative approaches between states and the bringing of order to the anarchical international system for the benefit of human rights, law, justice and economies.


The carnage of the First World War was principally responsible for the upsurge in Liberalist thinking. With Woodrow Wilson at the vanguard, the belief that conflict could be tamed and eventually vanquished through institutional order was applied with the creation of the League of Nations. As ambitious as it was ill-fated, the League was immediately undermined by the failure of the American legislature to ratify participation in an organisation that at least during its formative years enjoyed considerable public support (Knock 1992, p. 239).

Given that Realists had a long historical narrative of power-plays and conflicts from which to draw, it was little wonder they questioned the views of Liberalists during the later Inter-War period, labelling them Idealists or Utopians. Just as Liberalists regarded Realists as far too pessimistic about change and lacking in imagination to see the possibilities of cooperation and extension of law, diplomacy and security, so did Realists see their idealistic opponents as dangerously naïve.

Though Realists generally agreed that morality should be observed and even advanced, they felt these were best incubated in domestic environments made secure thanks to the state’s power. Loading security guarantees onto the weak shoulders of international bodies was seen as dangerous, given the risks posed to national survival if such arrangements failed. Indeed the very idea that the League could function as envisioned given the variety of states involved, their ideals and relative power, was suspect (Carr 1939, p.30). The actions of Germany, Italy and Japan throughout the 1930’s demonstrated the impotence of the League in the face of aggressive expansionism by revisionist states. The credibility of both it and Liberalism were seriously undermined, then finished off with the commencement of World War Two.

Realists had ammunition to effectively gun down the Liberalist case, and no one wielded the weapon more brutally than EH Carr in his 1939 text The Twenty Year’s Crisis. Carr’s contrasting of Realism and Liberalism, and his essential critique of the latter, was that ‘‘the complete realist, unconditionally accepting the causal sequence of events, deprives himself of the possibility of changing reality. The complete utopian, by rejecting the causal sequence, deprives himself of the possibility of understanding either the reality which he is seeking to change or the process by which it can be changed’’ (1939, p. 12).

Some dispute the need for such assaults. Lucian Ashworth charges that basic idealist tenets applied to Liberalist writers of the time did not accurately describe them, that this distorted debates they conducted between themselves and exaggerated their differences with Realists; altogether drastically oversimplifying the issue to the extent that Ashworth even questions calling this a Great Debate at all (2006, pp. 291-292). Indeed it can be suggested that a more pragmatic Liberalism enjoyed a revival following the War with the formation of international organisations, such as the United Nations, NATO, the EEC and its descendants, which have enjoyed accomplishments despite inherent issues. Also John Mearsheimer (2005, p. 140) points out that Idealism remains entrenched in the British school today – not the hallmark of a fatally undermined position.

Still, the bulk of the literature calls this Debate for Realists. The impact was that Realist theory found far greater respect in academic and policy circles than its rival, and indeed it is clear that Liberalism has since grown closer to Realist sentiment, as evidenced in the Neo-Neo debate discussed later. A negative impact was the effective ‘shutting out’ of alternative positions in the face of Realist dominance. This established a pattern in American and European academies, generally Realist and Liberalist respectively, where rebels were and are often given short shrift, ultimately doing no favours for the overall development of IR theory.


Taking place in the 1960’s, this was essentially a methodological debate revolving around the belief of Behaviouralists that IR could only advance itself by applying the methods of naturalist science. They believed that the field was too dominated by historians, who they labelled Traditionalists (or Classicists), who took the view that IR should be developed through more interpretive historicist methods. Behaviouralist focus was on the observation of systems and that those analyses, and any subsequent hypotheses and/or implying of causality, should be subject to empirical testing, mainly via falsification. That way knowledge in IR could be progressively built up, allowing for greater intuitions and progress in theory development (Kaplan 1966, p. 380).

The battle lines were drawn between the likes of Hedley Bull on the Traditionalist side, and Morton Kaplan on the Behaviouralist. There were other recognisable figures on either side, such as Carr and Schelling, as well as divisions within opposing camps, but Bull and Kaplan’s arguments get to the heart of the matter. Though acknowledging the swift rise of scientific methods in America, Traditionalists maintained that the ebbs and flows of global politics were necessarily interpretive, as one could not impose a neat system on a field with so many variables. An opposing Bull wrote of the method, that with such ‘‘strict standards of verification and proof there is very little of significance that can be said about international relations’’ (Bull 1966, p. 361). Kaplan countered that Traditionalism’s inherent breadth of analysis meant that its ‘‘generalizations are applied indiscriminately over enormous stretches of time and space. They are sufficiently loosely stated so that almost no event can be inconsistent with them’’ (1966, p.388) and thus would do nothing to enhance understanding or develop theory. For Behaviouralists, a theory that was not falsifiable was not a theory at all, more a subjective notion to be believed or disbelieved as suited (Sanders 2002, p. 50).

Behaviouralism was also critiqued over what its perceived weaknesses could bring to IR study. It had roots in positivism and so strict application would mean rejecting factors that could not be measured, such as human perception and motivation and would also prevent the development of normative theories since they focused on empirically non-testable ‘what ought to be’ (Sanders 2002, p. 51). As well as a charge of failing to grasp societal nuances, criticism was also levelled at Behaviouralism’s early practice of supposedly separating theory and values from observations. Behaviouralists countered these criticisms by largely recognising the potential value of knowledge produced by other methods of research, such as Kaplan’s acknowledgment of Bull’s contributions to arms control literature for example (1966, p. 388), but they reserved the right to test their own assumptions empirically. Behaviouralists even recognised and rectified their own perceived weaknesses, such as Hempel and Popper’s criticism of ‘narrow inductivist’ views and the impossibility of some kind of theory or values remaining absent from observation (not that it meant all theories were equal of course) (Sanders 2002, p. 52), thus placing positivism on a more deductive than inductive path.

Behaviouralism never sought to be a replacement theory, but a means of discovering one and facilitating Thomas Kuhn’s idea that ‘‘a new area of research spins off from an established one on the basis of a new exemplar’’ (Sharrock and Read 2002, p. 46). Whether its proponents intended it or not however, Behaviouralism became orthodoxy and Debate victor, its key strength over Traditionalism being the ability of researchers to replicate and analyse their colleagues’ processes and findings, with impacts including the encouragement of diligent and detailed work by IR theorists, and that positivist America came to be seen as a greater engine of political theory discourse.


Realism retained its dominant position, but real-world events such as the Vietnam conflict and the Oil Crisis forced it to reassess its core tenets. Kenneth Waltz’s 1979 Theory of International Politics aimed to reboot Realism, moving it on from a foundation in human nature towards a Structural Realism more associated with the international system, where Waltz recognised that units, i.e. nation states, could indeed co-act in such an anarchical environment, but that their functional similarities or differences would still determine the extent of such relations (1979, p. 104). Realism also took on a more scientific quality compared to past groundings in philosophy, history and human nature. It moved away from the kinds of generalised reflections Kaplan had criticised and towards precise statements and a vision of theory as advocated by Behaviouralists, earning it the label of Neorealism.

Behaviouralism’s impact also developed Liberalism’s precision and focus in what it sought to analyse, principally on how institutions could influence state behaviour through complex interdependence. Such integration scholarship emerged through the 1940’s and 1950’s, taking on a more regional tone in the 1960’s before a third transnational stage was advocated by Neoliberal institutional theorists (Lamy 2008, p. 132). Chief among them were Robert Keohane and Joseph Nye, who wished to emphasise the effects transnational relations had on the interstate system, especially in areas of national sovereignty, foreign policies, the challenges posed to international organisations and the impacts such a paradigm would have on equality balance between states and indeed the very study of IR (1972, p. xi). Neoliberalism edged closer to Neorealism with this acceptance of an anarchical system and state egoism, just as the latter came to accept interrelated entities espoused by the former.

Some question whether this situation merits the label of a ‘Great Debate’, including Wæver, who wrote: ‘‘Did it exist, the Inter-Paradigm Debate? Partly no, it was not actually an intense… debate occupying the mind of International Relationists, but an artificially constructed ‘debate’, mainly invented for specific presentational purposes, teaching and self-reflection of the discipline’’ (1996, p. 161). The ‘Inter-Paradigm’ term in the debate arises due to the two positions not so much being rivalling theories as they are paradigm positions, but as indicated above aspects of Neorealism and Neoliberalism still share common ground. While Neorealism viewed IR through a prism of competitive relations, Neoliberalism acknowledged this but also advocated the mutual benefits for states through greater cooperative relations (Lamy 2008, p. 132).

Ultimately both positions see reality as they want to, and so conclusions from empirical testing are inevitably influenced by the theory behind those observations (Wæver 1996, pp. 150-151). It can be said the Neorealism still focused on high politics and Neoliberalism on the low, but in accepting certain views and streamlining themselves and their methodologies, both positions were similar enough to give rise to a ‘Neo-Neo Synthesis’ and are incommensurable enough to co-exist, with each paradigm holding its own truth. One significant impact though was the rise of the poststructuralists to oppose this new Rationalist consensus (Wæver 2009, p. 215)


This most recent Debate, emerging in the mid-Eighties, is arguably one of the most serious. On one side Rationalists, inclusive of Realist and Liberalist positions, are positivistic in methodology, and while accepting the complexities of the social world, prefer to measure and analyse what can be observed. The opposition Reflectivists reject these positivist methods of knowledge generation, preferring interpretive and subjective study and a belief that values cannot be separate from observation (Kurki and Wight 2010, pp. 24-25). Given Rationalist paradigms have emerged through supposedly flawed and biased positivistic methodology, Reflectivists reject that system and any theorising within it.

Reflectivism includes such alternative approaches to IR theory as post-modernism, feminism, constructivism and critical theory (with emancipatory positions such as anti-colonialism capable of falling under the umbrella of the latter). Post-Modernism defies the self-fulfilling link between the status quo and the knowledge it generates, asking how ‘real truth’ can be discovered inside such a weighted system, while feminism views issues in IR through the lens of women, their place in world politics and gender issues (Smith and Owens, 2008, pp. 181-187). Critical theory is a Marxian spin-off that attempts to analyse, identify and assist emancipatory social changes (Hobden and Wyn Jones, 2008, p. 151). Constructivism is a social theory and has diverse facets itself, but is generally of the view that social ideas define the world and impact on material reality (Barnett 2008, pp. 162-163).

These are very basic presentations of positions that are far deeper and more complex, but the range of views is clear. Most agree on their opposition to the establishment but each has a distinct identity and priorities, and each theory can be diverse within itself. Richard Devetak observes that ‘‘the meaning of post-modernism is in dispute not just between proponents and critics, but also among proponents’’ (2001a, p. 181), while feminism alone comes in liberal, socialist, standpoint and post-modern varieties (Smith and Owens, 2008, pp. 181-184).

One criticism levelled at Reflectivists, that they seek to tear down the established order but fail to suggest anything new of their own, is unfair. For instance, post-modern IR theorists have suggested new conceptual language, so called ‘political prosaics’, to describe, for instance, the political dynamics of non-state groups or movements (Devetak 2001a, pp.198-199); while through critical theory’s analysis and interpretation of the state and communities, it has advocated normative arrangements for improving societies (Devetak 2001b, p.175). Rationalists like Keohane also suggest that if Reflectivists wish their views to be taken seriously then they should move beyond criticism into actually testing the validity of their claims through some form of research process (Kurki and Wight 2010, p. 25), though this of course is anathema to Reflectivists thus challenging them to a game they cannot participate in.

Given their differing group positions, internal discourses and inability to challenge Rationalists on their own terms, it has been difficult for Reflectivists to truly undermine the former; a difficult enough task without these issues, given the unlikelihood that Rationalists would ever willingly deconstruct their fundamental assumptions of IR. Yet over the duration of this Debate, some change has occurred. Kurki and Wight observe the significant rise of scientific realism, a complex position but essentially one that recognises a methodological pluralism between quantitative and qualitative methods, and has been incorporated in most constructivist thinking, giving rise to claims it now occupies a middle ground (2010, pp. 25-27). As Wæver also notes, an initial ‘‘polarised rationalism/reflectivism mutated into an axis, with more and more people located towards the middle, but still defining themselves in relation to this axis’’ (Wæver 2009, p. 217).


Debates can prompt rejuvenation, either through the triumph of new ideas or by strengthening established viewpoints. In IR there have been so many contentions that a great deal of fragmentation has occurred. This does not necessarily bode ill, as variety is essential to evolution. The principle negative is the competitive natures that have developed between opposing positions, so that alternatives have been undermined or fiercely refuted. This state of affairs may suit some, but it can be argued that as a result of such theoretical navel gazing, IR theory has been too preoccupied defining itself rather than analysing our world.

Still, through the process of the Great Debates IR theory has evolved. Aspects and results of one Debate helped prompt the conditions for the emergence of the next. It could even be suggested that the first three were more periodic discourses within one single overarching Great Debate that sought a definitive view of what IR as a discipline truly was, and gradually saw the main perspectives settle into a degree of synergy and acceptance of the different but significant roles of the nation state and international organisations. With that settled, a new Great Debate emerged between Rationalists and Reflectivists which, should the more radical elements of Reflectivist argument be accepted and applied, threatens the whole established model of theory and knowledge generation developed up until now.

Almost a century after its birth, IR is still in the process of defining itself. The Great Debates, whether like Wæver or Ashworth, one views them as less than full debates or not, still stimulated discussion about the essential characteristics of the discipline, and through these IR theory has undoubtedly advanced in complexity and nuance since its founding, and doubtless will continue to do so. Whatever happens in this latest Great Debate, surely it will not be the last.


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Written by: Iwan Benneyworth
Written at: School of European Studies, Cardiff University
Written for: Dr. Peter Sutch
Date written: December 2010

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