IR Theory and The Ontological Depth of the Material-Ideational Debate

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The questions that prompted the writing of this essay can be rephrased as follows: Is there a role to ideational factors in the study of International Relations (IR)? If so, is it possible to reconcile them with material factors in explanations of international politics? Being an advocate of theoretical pluralism, it was clear ab initio that I would be arguing for reconciliation while demonstrating the clear role of ideational factors in IR. Notwithstanding, the research done in order to provide informed answers to these questions, led me to conclude that an explicit address to the ontological depth of the material-ideational debate could be potentially valuable to the study of IR.

The relevance of this sort of metatheoretical analysis is clear. First, no IR analysis, or any theoretical analysis for that matter, has ever been ‘ontologically neutral’ (Hay, 2013). Ontological assumptions, i.e., ‘specification[s] of the object under study’ (Dunne et al., 2013: 415) are implied and logically precede any theory, regardless of whether we explicitly address them or not. Therefore, and since IR analyses and theories are no exception, explicitly addressing the nature and depth of its ontological assumptions is bound to be an insightful intellectual exercise.

What is the world of international politics actually made of? Is it physical or material? Is it ideational or abstract? Is it both? Are changes in international politics caused by material or ideational factors? These fundamental questions are not ‘best left for the philosophers’ (Monteiro and Ruby, 2009: 19). They are best explicitly addressed and answered by IR scholars. Indeed, an a priori exposition of one’s metatheoretical assumptions or ‘philosophical foundations’ (i.e., the ‘ontological and epistemological starting points for inquiry’ – Monteiro and Ruby, 2009: 25) can only further elucidate the theoretical position and arguments being put forward.

The main arguments of this essay can be logically summarized as follows: 1) Abstractions (knowledge and ideas) are real and the social world is composed by a material-ideational entanglement, which implies that 2) in explanations of social phenomena, the material and the ideational are not opposites nor discrete. Thus, 3) ideational factors are not only relevant, but ontologically indispensable in explanations of international politics, including those claiming otherwise. 4) If both factors are inextricably linked in reality and at the metatheoretical level (ontological reality), then there is logically nothing to reconcile at the theoretical level. There is only the recognition that the material-ideational dichotomy is misconceived, which 5) is the rationale behind the rise, usefulness and enhanced explanatory power of pluralistic or eclectic approaches in IR.

Framing the debate

In International Relations, the material-ideational debate revolves around determining which set of factors provides the basis for explanations of international politics. Yet, this debate transcends (or precedes) the discipline of IR. Indeed, it plagues all social disciplines: whereas some argue for the role of history, economics and technology, others argue for ideas, norms and identities (Raudino and Rendon, 2005). The reason for this is simple: due to its foundational character, this metatheoretical debate is imported from the Philosophy of Science to other academic fields, and IR is no exception. Foundations, at the ontological level, ‘define the kinds of things that exist in the world, which become the basic building blocks on which theories rely to explain phenomena’ (Monteiro and Ruby, 2009: 25).Indeed, as we shall see, unrecognized and overlooked ontological assumptions at the foundational level translate into ‘unrealistic analytical assumptions’ at the theoretical level (Hay, 2013).

In light of the above, I shall ontologically engage with the material-ideational debate in particular and more generally attempt to demonstrate the value and importance of explicitly addressing one’s philosophical foundations to the study of IR.

General considerations

The ‘essence of theorizing’ is, according to Reus-Smit (2020: 54),‘the use of assumptions to make sense of complexity’. The discipline of IR, in turn, ‘deals with the largest and most complicated social system possible’ (Lake, 2011: 467). Thus, it comes as no surprise that the quest to unravel such complexity has given rise to different theories with different sets of assumptions. Generally taken as the main unit of analysis in IR theories, are states – the main actors in the world of international politics (Lake, 2008). In explaining state behaviour, IR theories are often grouped into two categories: rationalist theories, which perceive states as equally self-interested and goal-oriented actors; and constructivist theories, which perceive states as distinct actors with differing interests, goals and identities. Whereas rationalist theorists assume material factors, such as military and economic power, as the main motivators of state behaviour; constructivist theorists take ideational factors, such as ideas and norms, instead. In the rationalist camp, neorealists like Mearsheimer (1995: 91) assume that ‘state behaviour is largely shaped by the material structureof the international system’, which means that the ‘distribution of material capabilities among states is the key factor for understanding world politics’. In contrast, from the point of view of constructivists such as Wendt (1999), ideas are necessary in order to define the meaning of material forces. Despite the fact that they are referred to as purely material – ‘things which exist and have certain powers independent of ideas’ (94). Nevertheless, both camps seem to agree that both material and ideational factors are relevant to the study of IR (Sørensen, 2008).

In summary, there is consensus in that both factors matter in explaining state behaviour, but rationalists isolate material factors (military and economic power) that enable states to survive and thrive in the international anarchy; and constructivists isolate abstract ideational factors (ideas and norms) that enable states to fulfil their identities and pursue their own socially constructed interests at the international level.

Positioning the essay

The position being put forward in this essay is dialectical or dualist in the sense that it considers the social world (including the world of international politics) as being composed by both materials (i.e., physical objects) and abstractions (i.e., human knowledge[1]), but idealist or constructivist in the sense that ideational factors have clear primacy over material ones in explaining international politics. In line with Wendt’s constructivist view, I maintain that though ‘material forces are not constituted solely by social meanings’ (1999: 111), it is on those meanings or ideational factors that we find the determinant causal power for explaining change in the social world. Put simply, human knowledge and ideas are the key factors in explaining social phenomena, including international politics. However, and in contradiction with many social constructivists, I defend that ideational factors and their causal power exist independently of our conceptualization of them. That they are substrate-independent[2], which is to say that knowledge and ideas have the ‘intriguing ability to take on a life of their own that’s rather independent of their physical substrate’ (Tegmark, 2017). And that their ‘causal mechanisms can exist independently of our knowledge of them’ (McAnulla 2005, 32). Indeed, as Joseph (2007: 354) concludes in his case for scientific realism in IR, ‘perhaps the answer to the question of the ontological status of objects, ideas, relations and structures is to say that they are all real’, that they ‘exist independently of our conceptualisation and have real powers, liabilities and causal effects’.

Ontological realism and the reality of abstractions. Following this thread, the philosophical foundations of this essay are thus in line with scientific realism. In essence, this is the idea that reality exists, and that knowledge of it can exist too (Deutsch, 2011). Thus, it is not a purely constructivist view because, as Wendt also concludes, ‘it cannot be ideas all the way down because scientific realism shows that ideas are based on and are regulated by an independently existing physical reality’ (Wendt, 1999: 110). Ontological realism is, then, the recognition that ‘at least a part of reality is ontologically independent of human minds’ (Niiniluoto, 2002: 1). Logically, this translates into 1) the natural world exists outside and independently of human minds; 2) the latter is dependent on the former; and 3) the social world is dependent on both. However, as alluded above, complex material systems (human brains and computers) have causally independent abstract phenomena (ideas and software programs, i.e., human knowledge) instantiated in them. Indeed, as Deutsch (2011: 114) points out ‘if your computer beats you at chess, it is really the program that has beaten you, not the silicon atoms or the computer as such’. This is to say that materialism is right in the sense that everything is composed of or dependent on matter, but wrong in assuming that matter is the only real and causal property in the world. Knowledge and abstractions – the by-products of human brains and computations, are real; and, as I shall argue, this insight has profound implications to one’s perception and understanding of the social world. Not least because this intrinsic entanglement between the abstract and the physical, and thus between the ideational and the material, exposes the use of the term ‘material’ when referring to social phenomena as ill-conceived. Indeed, as many constructivists have concluded, in the world of international politics even factors or forces that are referred to as ‘material’ have an abstract or ideational component attached to it – their ‘social loading’ (Dessler, 1999).

Reductionism and Causality

Ontological reductionism. One of the core arguments of this essay is, then, that there is no such thing as pure material forces (i.e., physical; atomic) in IR. That those forces, which are indeed relevant in explaining IR phenomena, are not simply ‘material’ but also laden with meaning. That when it comes to the social world, and especially to the macro-level of international politics, there is no avoiding knowledge and ideas in its explanations – even if one claims otherwise. Human knowledge is a force of nature capable of transforming the world (Deutsch, 2011), and, due to its substrate independence, those transformations are not explicable by sole reference or reduction into their material constituents. As Deutsch (2011) cleverly demonstrates, even if we reduced Sir Winston Churchill’s statue to the copper atoms that compose it and were somehow able to predict and describe their exact trajectory – from the copper mine to the sculptor’s studio, and so on… – that would tell us nothing about why those copper atoms are there. Therefore, given that causality in the social world is not explicable by atoms or material forces as such, but rather by human knowledge and ideas, we arrive at the concept of ontological individualism: ‘the view that human individuals are the sole, unique, and ultimate constituents of social reality to which all else is reducible’ (Hay, 2013: 2). In other words, without humans or, to be more precise, human minds and the knowledge they create, there would be no social world. Adding to Jon Elster (1989: 13) ‘the elementary unit of social life is the individual human action’ and the elementary (or causally relevant) unit of human action is human knowledge.

Put logically into context, this means that: if explanations of human behaviour require reference to ideational factors (knowledge and ideas), and if the fundamental driver of state behaviour (or of any other international actor) is human behaviour, then explanations of international politics that solely refer to material/physical factors (or at least claim to) are misconceived and ontologically orthogonal to the reality they purport to explain.

Individual-group and agent-structure relationships. Evidently, this is not to say that explanations of state behaviour lie at the individual level, as that would be akin to the ontological or material reductionism being criticized above. In this case, the misconception arises by disregarding the concept of levels of emergence: ‘sets of phenomena that can be explained well in terms of each other without analysing them into their constituent entities’ (Deutsch, 2011: 123). As Lake (2008: 45) explains, state behaviour cannot be reduced to the sum of its parts, as ‘no individual or group necessarily has direct interest in the systemically desirable actions that states are called upon to perform’. It can thus be said that the ‘group’, ‘whole’ or ‘domestic structure’ that is the state, cannot be reduced to its constituent ‘individuals’, ‘parts’ or ‘agents’ that are human minds. Yet, as Hay (2013: 12) notes, ‘dismantle the whole and we are left with the parts and “not them and some mysterious property which formerly held the whole thing together” (Ryan 1970, 181)’. Indeed, this ‘mysterious property’ is not mysterious at all. It is knowledge. Human knowledge and ideas that, not unlike genes[3], spread through human interaction and communication (verbal, written or otherwise). Given the substrate independence of knowledge, physical instantiations of it are not only in brains but also computers, official and unofficial institutional documents, books, etc. And, as long as human interaction and communication subsists, the emergent social structures of shared knowledge shall persist as well. Regarding the agency-structure problem, this implies that structure has no independent causal powers. That ‘agents and interaction are essential to the causal powers of structure; [and] to think otherwise is like thinking the mind exists or has effects apart from the brain.’ (Wendt, 1999: 146). Finally, it must be emphasized that more than a material structure, the international system is a structure of shared knowledge. And that only by taking the ‘shared’ component away, would the structure collapse into something that could (arguably) be considered strictly in material terms.

The social world can thus be thought of as the natural world turned into the ‘playground’ or ‘testing ground’ of human knowledge and ideas, which is the causality behind material transformations enacted by humans. Therefore, explanations of material changes in the structure of the international system lie not in the material structure itself, but in the structure of shared knowledge that lies underneath. Moreover, there is nothing in a given characteristic of the material structure of the international system that presents an ad eternum inevitable constraint to knowledge creation and human progress[4]. Indeed, as Wendt (1995: 78) famously noted: ‘An anarchy of friends differs from one of enemies, one of self-help from one of collective security, and these are all constituted by structures of shared knowledge’. Evidently, because the social world is physically instantiated in the natural world, any significant change to the latter shall indirectly affect the former. A simple example would be a natural disaster, which by directly affecting the territories of some states, indirectly affects the shared knowledge structure of the whole international system (e.g., by triggering other states to make donations)[5]. But, then again, to explain any instance of state behaviour (including a donation in response to a natural disaster) reference to its (ideational) causality is required.

Examples in International Politics

Canada/Cuba. Illustrative of the problems identified above is the ‘paradoxical’ difference in U.S.’s perceptions of, and actions toward, Canada and Cuba. Indeed, as Reus-Smit (2020: 62) points out ‘to the north of the US lies Canada, a rich middle power with significant military capacities, and to the south lies Cuba, a tiny impoverished developing state. Yet the US has long seen Cuba as a dire enemy.’ Evidently, by the neorealist’s logic of distribution and balance of material capabilities, this phenomenon is absurd and inexplicable. This is precisely due to the ontological assumption that the world of international politics ‘can be talked about without reference to values, reasons or ideological factors’ (Joseph, 2007: 348). Indeed, by relying on an ontological fallacy that reduces and considers causality in international politics as material, neorealism confines itself ab initio into a misconceived understanding and perception of the reality it purports to explain. An ontological realist, however, is able to understand this phenomenon. Indeed, regardless of material capabilities, a threatening perception of Cuban missiles, tanks and all other materials that compose its military power is created by the knowledge and meanings that the U.S. holds and attaches to Cuba itself. In contrast, and despite its significantly superior military power, an unthreatening perception of Canada is created. Thus, what creates these perceptions is the knowledge the U.S. has; and what explains U.S. behaviour is not the number of missiles and tanks, but the meanings attached to them. Finally, as argued above, it is obvious that material change indirectly affects its associated meanings, but it does not determine them, nor does it make them predictable. Even if both Canada and Cuba suddenly increased their military power by 50%, the explanation of how the U.S. would perceive and act upon those material changes would still reflect the aforementioned logic.

In effect, this exposes the ontologically mistaken ‘materialistic’ and oversimplified world view espoused by neorealism, which is rooted on the false and illusory idea that the material and the ideational are dichotomous and detachable factors in explanations of international politics. Nonetheless, and despite this ontological fallacy, the clear explanatory power that rationalist theories hold on many analyses of international politics deserves consideration. Indeed, sometimes states act like rational actors in a survival game; sometimes they act on what can be said to be their own utilitarian self-interest and, when they do, it makes perfect sense to use rationalist explanations. However, to think and claim to have found a fixed and inevitable pattern of state behaviour and/or a law of the material structure of the international system that somehow enables IR scholars to predict and explain the future of international politics, is to be completely mistaken about the very nature of the social world. Ironically, in an excellent critique of the privileging of ‘simplistic hypothesis testing’ in detriment of theory in IR, Mearsheimer and Walt (2013: 434), both proponents of neorealism, rightfully argue that ‘theories will produce sound hypotheses and useful explanations only if their components accurately reflect the real world’ – including the ‘unobservable’ in the theory’s ‘causal story’. This implies that a theory’s underpinning assumptions, including ontological ones, must also be (or, at least, propose to be) accurate reflections of reality. And thus, despite name similarity, their theoretical standpoint in the study of IR (neorealism) is contradictory and ontologically incompatible with their philosophical standpoint (scientific realism). But, indeed, as Hay (2013: 12) points out, ‘rational choice theorists seem prepared to accept the ontological irrealism of rational choice assumptions, defending such premises in terms of their analytical utility not their correspondence to an external reality’.

Nevertheless, the sheer number of inexplicable phenomena (exemplified above) and of failed predictions (exemplified below), should suffice to indicate that rationalist assumptions have clear limitations in analyses of international politics. And this recognition is, I argue, part of what explains the rise of pluralism and eclecticism in IR.

NATO’s Post-Cold War trajectory. Perhaps the quintessential example of a failed prediction in IR was NATO’s post-Cold War trajectory, which has been the subject of many (unsurprisingly pluralistic) IR analyses.[6] In the early 1990’s, when the collapse of the Soviet Union was imminent, the conventional wisdom in IR regarding NATO’s future was quite pessimistic. Neorealists in particular, predicted that NATO would lose its purpose and dissolve or, as Kenneth Waltz famously asserted, remain in existence but only on paper. Indeed, some scholars even went as far as arguing that European states would start ‘balancing’ against the U.S. The basis for these predictions was alliance theory, which posits that alliances are ‘formed as a balance against power or external threats, and when power shifts or threats disappear, so too do the reasons for alliances’ (Rauchhaus, 2000: 11). Logical as this may seem, its prediction was in complete opposition to the reality that unfolded. Indeed, since the end of the Cold War, NATO has not only survived but also thrived in many respects (Duffield, 2018). Unsurprisingly, the explanation of this failure lies in the ontological limitations of neorealist thought. By myopically focusing on the ‘material’ capabilities of states and their shifts in the international structure, neorealists see NATO as a mere cluster of states that were inevitably brought together by the structure in which they are instantiated in.

Constructivists, on the other hand, place their emphasis on the promotion of transatlantic values (democracy, capitalism, etc.); on the teaching of norms and how they shape state preferences. Therefore, as Rauchhaus (2000: 17) concludes, ‘constructivists would be the least surprised by NATO’s post-Cold War success’, as they take into account not only NATO’s organizational attributes, but also the fact that it is nested in a transatlantic security community. Thus, by explicitly emphasizing ideational factors, constructivism takes an ontological position that better reflects the world of international politics, enabling it to go beyond ‘material’ factors and achieve further explanatory power. Indeed, ‘if we are to understand path-shaping institutional change we must acknowledge the independent causal and constitutive role of ideas’ (Marsh, 2009: 684). In effect, this is demonstrated by Gheciu’s (2005) analysis of NATO’s post-Cold War enlargement where she rightfully concludes that, contrary to any rationalist logic, NATO’s post-Cold War trajectory was a ‘complex process of projecting liberal democratic norms – thus extending the Western community – into Central and Eastern Europe’ (232). In other words, the spread of (good) ideas and change in structures of shared knowledge.


In the light of the above, the main argument of this essay is that ideational factors do not simply matter in explanations of international politics – they are fundamental to them. The explanation of causality and change in the social world is in the knowledge and ideas that bring them about, not in the materials where they are physically instantiated in (vide chess program example), not in the materials affected by them (vide Churchill’s statue example), and not in the materials that they refer to (vide Canada/Cuba example). Therefore, though explanations of international politics naturally refer to observable material factors, their explanatory power and the causal story they tell are primordially about ideational factors (vide NATO example).

The observable material surface evidently provides important cues for us to reasonably conjecture what is happening and, perhaps more importantly, to rule out what is not happening in the unobservable abstract depth. But to reduce the latter to inevitable patterns of utilitarian behaviour, and to attribute the causal power of social phenomena to the structure of the former, is to grossly oversimplify the complexity, importance and creative nature of human beings and their social world. The result of this dire view is, as Finnemore and Sikkink (1998: 917) point out, ‘politics without passion or principles, which is hardly the politics of the world in which we live’. Indeed, and fortunately, empirical research on norms has shown time and again how people’s ideas on what ought to be become an is in political reality (Finnemore and Sikking, 1998).

The Ontological Case for Theoretical Pluralism

In arguing that material assumptions in IR theories are, in fact, ‘material’ this essay also intended to bring forth an important point on the rise of eclecticism in IR. Indeed, it is no coincidence that theoretical pluralism is a valuable asset to IR analyses, and that both rationalist and constructivist approaches have explanatory power even when referring to the same phenomena in different ways. NATO, for instance, can be conceptualized in three different ways: as an alliance, as an institution and as a community, which, in turn, is respectively associated with neorealism, neoliberalism and constructivism (Webber, 2012: 9). Hyde-Price (2016: 31) concludes that this is because NATO, ‘like the international system within which it is embedded, is stratified into various layers and domains that require different concepts, assumptions and principles of explanation’. In effect, this attributes the compatibility between different theories to the complexity of the international system. And to say that the object under study is complex, means, theoretically speaking, ontological complexity. It follows then that the compatibility between IR theories lies at the ontological level. That despite having different sets of assumptions, IR theories are ontologically compatible. Yet, if rationalists isolate material factors and constructivists isolate ideational factors, how are they ontologically compatible? The common answer is that both are right. That the complexity of the international system is such that to explain its phenomena one requires two fundamental causal powers (material and ideational). But I argue otherwise.

Instead of arguing that both are right, I argue that only constructivists are right in what they explicitly say. I argue that the international system is explicable by reference to one fundamental causal power alone (ideational), and that despite labelling it as ‘material’ rationalists also refer to it. What happens is that rationalists implicitly personify and endow materials with powers that can only be attributed to human knowledge, but then explicitly refer to them as if they were purely material.

Thus, albeit implicitly and explicitly, both rationalists and constructivists are referring to ideational factors to explain change in international politics. The source of causality – human knowledge – is the same. Therefore, nothing is inevitable or unchangeable in the world of international politics (including its structure). Indeed, the only laws applicable to both materials and knowledge are the laws of physics. And the laws of physics tell us nothing about the anarchical structure of the international system.

Therefore, the compatibility and complementarity of IR theories; the rise and analytical superiority of theoretical pluralism; and the fact that ‘the dictates of realism’ (Mearsheimer, 1995: 337) only work sometimes, is all explicable by the ontological assumption that IR theories and explanations inevitably refer to the same unpredictable source of causality – human knowledge.

In conclusion, ‘material’ and ideational factors are not reconcilable in IR theory because there is nothing to be reconciled in the first place. It is the alleged dichotomy itself that is irreconcilable with the ontological reality of international politics. Therefore, ‘reconciliation’ comes not at the theoretical level, but at the metatheoretical level by adopting ontological realism and understanding that material factors in IR are ‘material’. Only then, given the unpredictable and complex ontological nature of IR phenomena, comes the reasonable conclusion that IR theories is superior to IR theory. For there is no way to predict which theory shall be useful next.


Barany, Z. and Rauchhaus, R. (2011). Explaining NATO’s Resilience: Is International Relations Theory Useful? Contemporary Security Policy, 32(2), pp.286–307.

Basu, S. (2019). The False Dichotomy of the Material-Ideational Debate in IR Theory. [online] Available at:

Checkel, Jeffrey T. International norms and domestic politics: Bridging the rationalist—Constructivist divide. European journal of international relations 3, no. 4 (1997): 473-495.

Dawkins, R., 2016. The Selfish Gene. Oxford University Press.

Dessler, D. (1999). Constructivism within a positivist social science. Review of International Studies, 25(1), pp.123–137.

Deutsch, D. (1998). The fabric of reality. London: Penguin.

Deutsch, D. (2011). The Beginning of Infinity. Penguin Books.

Duffield. (2018). Security Studies: An Introduction, Taylor & Francis Group, Milton.

Dunne, T., Hansen, L. and Wight, C. (2013). The end of International Relations theory? European Journal of International Relations, 19(3), pp.405–425.

Elster, J. (1989). Nuts and Bolts for the Social Sciences. Cambridge: Cambridge University Press.

Finnemore, Martha, and Kathryn Sikkink. (1998). International norm dynamics and political change. International organization: 887-917.

Gheciu, A. (2005). NATO in the “New Europe”: The Politics of International Socialization after the Cold War.

Hay, C. (2013). Political Ontology. The Oxford Handbook of Political Science.

Humphreys, A.R.C. (2007). Kenneth Waltz and the limits of explanatory theory in international relations.

Joseph, J. (2007). Philosophy in International Relations: A Scientific Realist Approach, Millennium, 35(2), pp. 345–359.

Lake, D.A. (2008). Chapter 2 ‘The State and International Relations’. The Oxford Handbook of International Relations.

Lake, D.A. (2011). Why “isms” Are Evil: Theory, Epistemology, and Academic Sects as Impediments to Understanding and Progress. International Studies Quarterly, 55(2), pp.465–480.

Lake, D. A. (2013). Theory is dead, long live theory: The end of the Great Debates and the rise of eclecticism in International Relations, European Journal of International Relations, 19(3), pp. 567–587.

Marsh, D. (2009). Keeping Ideas in their Place: In Praise of Thin Constructivism. Australian Journal of Political Science, 44(4), pp.679–696.

McAnulla, S. 2005. Making Hay with Actualism? The Need for a Realist Concept of Structure. Politics 25(1): 31–8.

Mearsheimer, J.J. (1994) The False Promise of International Institutions., 19 (3): 5–49.

Mearsheimer, J.J. (1995) ‘A Realist Reply’, International Security 20(1): 82–93.

Mearsheimer, J. J. and Walt, S. M. (2013) ‘Leaving theory behind: Why simplistic hypothesis testing is bad for International Relations’, European Journal of International Relations, 19(3), pp. 427–457.

Monteiro, N. P. and Ruby, K. G. (2009). IR and the false promise of philosophical foundations. International Theory. Cambridge University Press, 1(1), pp. 15–48.

Moreira, A. C. (2020). Can International Relations theory tell us anything useful about NATO? [Unpublished manuscript]. College of Social Sciences, University of Birmingham.

Niiniluoto, I. (2002). Realism in Ontology. In Critical Scientific Realism. Oxford University Press.

Popper, K. R. (1968). The logic of scientific discovery. New York, Harper & Row.

Popper, K. R. (1971). The open society and its enemies. Princeton, N.J., Princeton University Press.

Rauchhaus, R.W. (2000). Marching NATO eastward: Can international relations theory keep pace? Contemporary Security Policy, 21(2), pp.3–20.

Raudino, S. and Rendon, E. (2005). Material forces and the force of ideas: Interview with Robert Gilpin. The International Spectator, 40(1), pp.99–105.

Reus-Smit, C., 2020. International Relations: A Very Short Introduction. Oxford University Press.

Sørensen, G. (2008). The Case for Combining Material Forces and Ideas in the Study of IR. European Journal of International Relations, 14(1), pp.5–32.

Tegmark, M. (2017). Substrate-independence in [online] Available at:

Waltz, K.N. (2000) NATO expansion: A realist’s view., 21 (2): 23–38.

Webber M., Sperling J., Smith M.A. (2012) Thinking NATO through Theoretically. In: NATO’s Post-Cold War Trajectory. New Security Challenges Series. Palgrave Macmillan, London.

Webber, M., Hyde-Price, A. (2016). Theorising NATO: New perspectives on the Atlantic alliance.

Wendt, A. (1995). Constructing International Politics. International Security, 20(1), pp.71–81.

Wendt, A., (1999). Social Theory of International Politics. Cambridge University Press.

[1]Ideas and norms = Human knowledge.

[2]Coined by Alan Turing who proved the substrate-independence of computations, this intriguing concept has been applied to conscious processes (Tegmark, 2017) and to knowledge (Deutsch, 2011).

[3] This idea of perceiving the spread of ideas (‘memes’) as akin to the spread of genes through processes of variation and selection was made famous by Richard Dawkins in his book ‘The Selfish Gene’.

[4] As Deutsch (2011) points out, knowledge creation is bound only by the laws of physics.

[5] This also serves as an example of how shared knowledge structures transcend territorial and material boundaries.

[6] For instance, Barany and Rauchhaus (2011), Webber (2012) and Hyde-Price (2016).

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