International Relations

… a core concept in Global Context and Atlas105

Concept description

Writing in the Encyclopaedia Britannica, Charles McClelland and Robert Pfaltzgraff (2016, reference below) define international relations as “the study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies, political parties, and interest groups) [and] is related to a number of other academic disciplines, including political science, geography, history, economics, law, sociology, psychology, and philosophy.”

Principal theories of international relations

In her 2011 review chapter (reference below), Anne-Marie Slaughter identifies six principal theories (see pdf link below for citations):

Realism [see also the separate Atlas entry, Realism]

“For Realists (sometimes termed ‘structural Realists’ or ‘Neorealists’, as opposed to the earlier ‘classical Realists’) the international system is defined by anarchy – the absence of a central authority (Waltz). States are sovereign and thus autonomous of each other; no inherent structure or society can emerge or even exist to order relations between them. They are bound only by forcible coercion or their own consent.

“In such an anarchic system, State power is the key – indeed, the only – variable of interest, because only through power can States defend themselves and hope to survive. Realism can understand power in a variety of ways – eg militarily, economically, diplomatically – but ultimately emphasizes the distribution of coercive material capacity as the determinant of international politics. …

“Realists’ overriding emphasis on anarchy and power leads them to a dim view of international law and international institutions (Mearsheimer 1994). Indeed, Realists believe such facets of international politics to be merely epiphenomenal; that is, they reflect the balance of power, but do not constrain or influence State behaviour. In an anarchic system with no hierarchical authority, Realists argue that law can only be enforced through State power. But why would any State choose to expend its precious power on enforcement unless it had a direct material interest in the outcome? And if enforcement is impossible and cheating likely, why would any State agree to co-operate through a treaty or institution in the first place?

Thus States may create international law and international institutions, and may enforce the rules they codify. However, it is not the rules themselves that determine why a State acts a particular way, but instead the underlying material interests and power relations. International law is thus a symptom of State behaviour, not a cause.”


“Institutionalists share many of Realism’s assumptions about the international system – that it is anarchic, that States are self-interested, rational actors seeking to survive while increasing their material conditions, and that uncertainty pervades relations between countries. However, Institutionalism relies on microeconomic theory and game theory to reach a radically different conclusion – that co-operation between nations is possible.

“The central insight is that co-operation may be a rational, self-interested strategy for countries to pursue under certain conditions (Keohane 1984). Consider two trading partners. If both countries lower their tariffs they will trade more and each will become more prosperous, but neither wants to lower barriers unless it can be sure the other will too. Realists doubt such co-operation can be sustained in the absence of coercive power because both countries would have incentives to say they are opening to trade, dump their goods onto the other country’s markets, and not allow any imports.

“Institutionalists, in contrast, argue that institutions – defined as a set of rules, norms, practices and decision-making procedures that shape expectations – can overcome the uncertainty that undermines co-operation. First, institutions extend the time horizon of interactions, creating an iterated game rather than a single round. Countries agreeing on ad hoc tariffs may indeed benefit from tricking their neighbors in any one round of negotiations. But countries that know they must interact with the same partners repeatedly through an institution will instead have incentives to comply with agreements in the short term so that they might continue to extract the benefits of co-operation in the long term. Institutions thus enhance the utility of a good reputation to countries; they also make punishment more credible.

“Second, Institutionalists argue that institutions increase information about State behaviour. Recall that uncertainty is a significant reason Realists doubt co-operation can be sustained. Institutions collect information about State behaviour and often make judgments of compliance or non-compliance with particular rules. States thus know they will not be able to ‘get away with it’ if they do not comply with a given rule.

“Third, Institutionalists note that institutions can greatly increase efficiency. It is costly for States to negotiate with one another on an ad hoc basis. Institutions can reduce the transaction costs of co-ordination by providing a centralized forum in which States can meet. They also provide ‘focal points’ – established rules and norms – that allow a wide array of States to quickly settle on a certain course of action. Institutionalism thus provides an explanation for international co-operation based on the same theoretical assumptions that lead Realists to be skeptical of international law and institutions.

“One way for international lawyers to understand Institutionalism is as a rationalist theoretical and empirical account of how and why international law works. Many of the conclusions reached by Institutionalist scholars will not be surprising to international lawyers, most of whom have long understood the role that reciprocity and reputation play in bolstering international legal obligations. At its best, however, Institutionalist insights, backed up by careful empirical studies of international institutions broadly defined, can help international lawyers and policymakers in designing more effective and durable institutions and regimes.”


“Liberalism makes for a more complex and less cohesive body of theory than Realism or Institutionalism. The basic insight of the theory is that the national characteristics of individual States matter for their international relations. This view contrasts sharply with both Realist and Institutionalist accounts, in which all States have essentially the same goals and behaviours (at least internationally) – self-interested actors pursuing wealth or survival. Liberal theorists have often emphasized the unique behaviour of liberal States, though more recent work has sought to extend the theory to a general domestic characteristics-based explanation of international relations.

“One of the most prominent developments within liberal theory has been the phenomenon known as the democratic peace (Doyle). First imagined by Immanuel Kant, the democratic peace describes the absence of war between liberal States, defined as mature liberal democracies. Scholars have subjected this claim to extensive statistical analysis and found, with perhaps the exception of a few borderline cases, it to hold (Brown Lynn-Jones and Miller). Less clear, however, is the theory behind this empirical fact. Theorists of international relations have yet to create a compelling theory of why democratic States do not fight each other. Moreover, the road to the democratic peace may be a particularly bloody one; Edward Mansfield and Jack Snyder have demonstrated convincingly that democratizing States are more likely to go to war than either autocracies or liberal democracies.

“Andrew Moravcsik has developed a more general liberal theory of international relations, based on three core assumptions: (i) individuals and private groups, not States, are the fundamental actors in world politics (Non-State Actors); (ii) States represent some dominant subset of domestic society, whose interests they serve; and (iii) the configuration of these preferences across the international system determines State behaviour (Moravcsik). Concerns about the distribution of power or the role of information are taken as fixed constraints on the interplay of socially-derived State preferences.

“In this view States are not simply ‘black boxes’ seeking to survive and prosper in an anarchic system. They are configurations of individual and group interests who then project those interests into the international system through a particular kind of government. Survival may very well remain a key goal. But commercial interests or ideological beliefs may also be important. …”


“Constructivism is not a theory, but rather an ontology: A set of assumptions about the world and human motivation and agency. Its counterpart is not Realism, Institutionalism, or Liberalism, but rather Rationalism. By challenging the rationalist framework that undergirds many theories of international relations, Constructivists create constructivist alternatives in each of these families of theories.

“In the Constructivist account, the variables of interest to scholars – eg military power, trade relations, international institutions, or domestic preferences – are not important because they are objective facts about the world, but rather because they have certain social meanings (Wendt 2000). This meaning is constructed from a complex and specific mix of history, ideas, norms, and beliefs which scholars must understand if they are to explain State behaviour. For example, Constructivists argue that the nuclear arsenals of the United Kingdom and China, though comparably destructive, have very different meanings to the United States that translate into very different patterns of interaction (Wendt 1995). To take another example, Iain Johnston argues that China has traditionally acted according to Realist assumptions in international relations, but based not on the objective structure of the international system but rather on a specific historical strategic culture.

“A focus on the social context in which international relations occur leads Constructivists to emphasize issues of identity and belief (for this reason Constructivist theories are sometimes called ideational). The perception of friends and enemies, in-groups and out-groups, fairness and justice all become key determinant of a State’s behaviour. While some Constructivists would accept that States are self-interested, rational actors, they would stress that varying identities and beliefs belie the simplistic notions of rationality under which States pursue simply survival, power, or wealth.

“Constructivism is also attentive to the role of social norms in international politics. Following March and Olsen, Constructivists distinguish between a ‘logic of consequences’ – where actions are rationally chosen to maximize the interests of a State – and ‘logic of appropriateness’, where rationality is heavily mediated by social norms. For example, Constructivists would argue that the norm of State sovereignty has profoundly influenced international relations, creating a predisposition for non-interference that precedes any cost-benefit analysis States may undertake. These arguments fit under the Institutionalist rubric of explaining international co-operation, but based on constructed attitudes rather than the rational pursuit of objective interests.

“Perhaps because of their interest in beliefs and ideology, Constructivism has also emphasized the role of non-State actors more than other approaches. For example, scholars have noted the role of transnational actors like NGOs or transnational corporations in altering State beliefs about issues like the use of land mines in war or international trade. Such ‘norm entrepreneurs’ are able to influence State behaviour through rhetoric or other forms of lobbying, persuasion, and shaming (Keck and Sikkink). Constructivists have also noted the role of international institutions as actors in their own right. While Institutionalist theories, for example, see institutions largely as the passive tools of States, Constructivism notes that international bureaucracies may seek to pursue their own interests (eg free trade or human rights protection) even against the wishes of the States that created them (Barnett and Finnemore).”

The English School

“The English School shares many of Constructivism’s critiques of rationalist theories of international relations. It also emphasizes the centrality of international society and social meanings to the study of world politics (Bull). Fundamentally, however, it does not seek to create testable hypotheses about State behaviour as the other theories do. Instead, its goals are more similar to those of a historian. Detailed observation and rich interpretation is favored over general explanatory models. Hedley Bull, for instance, a leading English School scholar, argued that international law was one of five central institutions mediating the impact of international anarchy and instead creating ‘an anarchical society’.

“Given their emphasis on context and interpretive methods, it is no surprise that English School writers hold historical understandings to be critical to the study of world politics. It is not enough simply to know the balance of power in the international system, as the Realists would have it. We must also know what preceded that system, how the States involved came to be where they are today, and what might threaten or motivate them in the future. Domestic politics are also important, as are norms and ideologies.”

Critical Approaches

“The dominant international relations theories and their underlying positivist epistemology have been challenged from a range of perspectives. Scholars working in Marxist, feminist, post-colonial, and ecological fields have all put forward critiques of international relations’ explanations of State behaviour (Colonialism; Developing Country Approach to International Law; Feminism, Approach to International Law). Most of these critiques share a concern with the construction of power and the State, which theories like Realism or Institutionalism tend to take for granted.

“For example, Marxist scholars perceive the emphasis on State-to-State relations as obscuring the more fundamental dynamics of global class relations (Marxism). Only by understanding the interests and behaviour of global capital can we make sense of State behaviour, they argue (Cox and Sinclair). Similarly, feminists have sought to explain aspects of State behaviour and its effects by emphasizing gender as a variable of interest (Ackerly Stern and True). This focus has lead, for example, to notions of security that move beyond State security (of paramount importance to Realists) to notions of human security. In such a perspective the effects of war, for example, reach far beyond the battlefield to family life and other aspects of social relations.”

Slaughter concludes her review of the principal theories of international relations with:

“While many theories of international relations are fiercely contested, it is usually inappropriate to see them as rivals over some universal truth about world politics. Rather, each rests on certain assumptions and epistemologies, is constrained within certain specified conditions, and pursues its own analytic goal. While various theories may lead to more or less compelling conclusions about international relations, none is definitively ‘right’ or ‘wrong’. Rather, each possesses some tools that can be of use to students of international politics in examining and analyzing rich, multi-causal phenomena.”

In a 2017 review, Jonathan Cristol (reference below) consolidates the various strands of international relations theory into “the three major branches”: Realism, Liberalism, and Constructivism, asserting that:

“These three branches have replaced the earlier realism-idealism dichotomy. … Critical IR theory and Feminist IR theory are often considered part of constructivism; however, there is much debate over whether they constitute their own branches … Post–Cold War IR Theory is given its own heading because there are a number of theories that were proposed in the immediate aftermath of the Cold War that are still widely taught and discussed in the field. Perhaps the most controversial inclusion is that of Neoconservatism. Though it is quite possible to mount a case for it to be considered a theory of US foreign policy, it is theoretically distinct from other IR theories (the belief in bandwagoning instead of balancing).

Scholars and practitioners in international relations

McClelland and Pfaltzgraff (2016) write:

“The study of international relations has always been heavily influenced by normative considerations. … As the field of international relations evolved during the tumultuous 20th century, the need to find nonviolent means of settling international disputes was a recurrent theme. This theme has been manifest in “world order thinking,” which is usually traced to the approach to international relations espoused by President Wilson and set forth in his Fourteen Points for the post-World War I era. Proponents of world order thinking place major, if not primary, emphasis on building international organizations, strengthening international law, and fostering greater trust between countries. World order thinking, which gives primacy to international interest over national interest, addresses issues such as the possibility of just war; the distinction between wars of self-defense and wars of aggression; the elements of international justice, including equality of countries; the protection of human rights, including the legal and political justifications for international intervention in response to cases of internal ethnic cleansing and genocide; as well as issues related to global environmental problems resulting from population growth, urbanization, resource depletion, and pollution.

“The normative agenda of international relations emerges from the context of the times, the focus changing depending on an era’s most pressing problems. The result is the identification of new topics that both shape international relations research and analysis and lead to a quest for innovative policies. At the beginning of the 21st century, research focused on issues such as terrorism, religious and ethnic conflict, the breakup of states, the emergence of substate and nonstate entities, the spread of weapons of mass destruction and efforts to counter nuclear proliferation, and the development of international institutions.

“The differences between the interests of scholars and those of practitioners of international affairs often have appeared to be more important than the similarities. Scholars, who often are committed to a world order fundamentally different from the existing one, usually have sought to avoid both the fact and the reputation of serving as apologists for official foreign policies. The principle of scientific detachment in social-science research also has contributed to the scholarly effort to evaluate international events and developments from a global perspective rather than from that of any one country’s foreign policy.

“By contrast, practitioners have been more inclined to indifference than to hostility in their attitudes toward academics in international relations. They frequently have professed that they have found little in the field that is of value in their day-to-day work. There are few signs of direct influence in either direction, though there have been indirect and subtle exchanges that have been important in the conduct of foreign relations. …

“The indirect influence of international relations studies on governmental thinking and policy making has been apparent in a number of noteworthy areas since the mid-20th century. The realist formulation of power politics, for example, has filtered into the foreign-policy thinking of the United States government to such an extent that foreign-policy decisions sometimes have been defended by arguments based on national interest and calculations of power, and opposing views have been dismissed as reflecting insufficient “hard-nosed” realism. In addition, U.S. foreign-policy decision making in times of crisis has been influenced by scholarly studies such as Graham Allison’s Essence of Decision: Explaining the Cuban Missile Crisis (1971). During the Cold War, deterrence theories developed in the civilian sector, often by academic specialists, became the essential basis for strategic nuclear planning. The theoretical and operational aspects of deterrence received renewed attention from both scholars and policy makers as new actors and new weapons of mass destruction arose at the end of the 20th century. …

“Whether the relationships between scholars and practitioners of international relations will be strengthened remains to be seen. Theories of international relations were notably deficient in their ability to predict the end of the Cold War. Moreover, the dramatic and accelerating changes that have transformed the world since the end of the 20th century have enhanced the problems inherent in developing accurate appraisals of the world in its international aspect. Nonetheless, there is a consensus that more sophisticated uses of quantitative, computer-assisted studies in universities, research organizations, and governments will aid researchers in their quest to better understand and explain the current state of the world and to produce more frequent and precise reports. The academic community, however, has generally lacked adequate resources and trained personnel to satisfy the growing demand for information.”

Atlas topic, subject, and course

The Study of Global Affairs and International Relations (core topic) in Global Context and Atlas105.


Charles McClelland and Robert Pfaltzgraff (2016), International relations, Encyclopaedia Britannica, at, accessed 11 March 2019.

Anne-Marie Slaughter (2011), International Relations – Principal Theories, in Wolfrum, R. (Ed.) Max Planck Encyclopedia of Public International Law (Oxford University Press, 2011), at, accessed 11 March 2011.

Jonathan Cristol (2017), International Relations Theory, Oxford Bibliographies, at, accessed 11 March 2019.

Page created by: Ian Clark, last modified 11 March 2019.

Image: Jagran Josh, at, accessed 11 March 2019.