Chapter 4: International Relations Theory

Theories of International Relations allow us to understand and try to make sense of the world around us through various lenses, each of which represents a different theoretical perspective. In order to consider the field as a whole for beginners it is necessary to simplify IR theory. This chapter does so by situating IR theory on a three-part spectrum of traditional theories, middle-ground theories and critical theories. Examples are used throughout to help bring meaning and perspective to these positions. Readers are also encouraged to consult this book’s companion text, International Relations Theory (forthcoming 2017), which expands greatly on the subject matter of this chapter. Before we get started, one very important note. You may notice that some of the theories you are introduced to here are referred to by names that also occur in other disciplines. Sometimes this can be confusing as, for example, realism in IR is not the same as realism in art. Similarly, you may hear the word ‘liberal’ being used to describe someone’s personal views, but in IR liberalism means something quite distinct. To avoid any confusion, this note will serve as a caveat that in this chapter we only refer to the theories concerned as they have been developed within the discipline of International Relations.

Traditional theories

Theories are constantly emerging and competing with one another. For that reason it can be disorientating to learn about theoretical approaches. As soon as you think you have found your feet with one approach, you realise there are many others. Thomas Kuhn’s The Structure of Scientific Revolutions (1962) set the stage for understanding how and why certain theories are legitimised and widely accepted. He also identified the process that takes place when theories are no longer relevant and new theories emerge. For example, human beings were once convinced the earth was flat and accepted this as fact. With the advancement of science and technology, humans discarded this previously accepted belief. Once such a discovery takes place, a ‘paradigm shift’ results and the former way of thinking is replaced with a new one. Although changes in IR theory are not as dramatic as the example above, there have been significant evolutions in the discipline. This is important to keep in mind when we consider how theories of IR play a role in explaining the world and how, based upon different time periods and our personal contexts, one approach may speak to us more than another. Traditionally there have been two central theories of IR: liberalism and realism. Although they have come under great challenge from other theories, they remain central to the discipline.

At its height, liberalism in IR was referred to as a ‘utopian’ theory and is still recognised as such to some degree today. Its proponents view human beings as innately good and believe peace and harmony between nations is not only achievable, but desirable. Immanuel Kant developed the idea in the late eighteenth century that states that shared liberal values should have no reason for going to war against one another. In Kant’s eyes, the more liberal states there were in the world, the more peaceful it would become, since liberal states are ruled by their citizens and citizens are rarely disposed to desire war. This is in contrast to the rule of kings and other non-elected rulers who frequently have selfish desires out of step with citizens. His ideas have resonated and continue to be developed by modern liberals, most notably in the democratic peace theory, which posits that democracies do not go to war with each other, for the very reasons Kant outlined.

Further, liberals have faith in the idea that the permanent cessation of war is an attainable goal. Taking liberal ideas into practice, US President Woodrow Wilson addressed his famous ‘Fourteen Points’ to the US Congress in January 1918 during the final year of the First World War. As he presented his ideas for a rebuilt world beyond the war, the last of his points was to create a general association of nations, which became the League of Nations. Dating back to 1920, the League of Nations was created largely for the purpose of overseeing affairs between states and implementing, as well as maintaining, international peace. However, when the League collapsed due to the outbreak of the Second World War in 1939, its failure became difficult for liberals to comprehend, as events seemed to contradict their theories. Therefore, despite the efforts of prominent liberal scholars and politicians such as Kant and Wilson, liberalism failed to retain a strong hold and a new theory emerged to explain the continuing presence of war. That theory became known as realism.

Realism gained momentum during the Second World War when it appeared to offer a convincing account for how and why the worst conflict in known history originated after a period of supposed peace and optimism. Although it originated in named form in the twentieth century, many realists have traced its origins in earlier writings. Indeed, realists have looked as far back as to the ancient world where they detected similar patterns of human behaviour as those evident in our modern world. As its name suggests, advocates of realism purport it reflects the ‘reality’ of the world and more effectively accounts for change in international politics. Thomas Hobbes is often mentioned in discussions of realism due to his description of the brutality of life during the English Civil War of 1642–1651. Hobbes described human beings as living in an orderless ‘state of nature’ that he perceived as a war of all against all. To remedy this, he proposed that a ‘social contract’ was required between a ruler and the people of a state to maintain relative order. Today, we take such ideas for granted as it is usually clear who rules our states. Each leader, or ‘sovereign’ (a monarch, or a parliament for example) sets the rules and establishes a system of punishments for those who break them. We accept this in our respective states so that our lives can function with a sense of security and order. It may not be ideal, but it is better than a state of nature. As no such contract exists internationally and there is no sovereign in charge of the world, disorder and fear rules international relations. That is why war seems more common than peace to realists, indeed they see war as inevitable. When they examine history they see a world that may change in shape, but is always characterised by a system of what they call ‘international anarchy’ as the world has no sovereign to give it order.

One central area that sets realism and liberalism apart is how they view human nature. Realists do not typically believe that human beings are inherently good, or have the potential for good, as liberals do. Instead, they claim individuals act in their own self-interests. For realists, people are selfish and behave according to their own needs without necessarily taking into account the needs of others. Realists believe conflict is unavoidable and perpetual and so war is common and inherent to humankind. Hans Morgenthau, a prominent realist, is known for his famous statement ‘all politics is a struggle for power’ (Morgenthau 1948). This demonstrates the typical realist view that politics is primarily about domination as opposed to cooperation between states. Here, it is useful to briefly recall the idea of theories being lenses. Realists and liberals look at the very same world. But when viewing that world through the realist lens, the world appears to be one of domination. The realist lens magnifies instances of war and conflict and then uses those to paint a certain picture of the world. Liberals, when looking at the same world, adjust their lenses to blur out areas of domination and instead bring areas of cooperation into focus. Then, they can paint a slightly different picture of the same world.

It is important to understand that there is no single liberal or realist theory. Scholars in the two groups rarely fully agree with each other, even those who share the same approach. Each scholar has a particular interpretation of the world, which includes ideas of peace, war and the role of the state in relation to individuals. And, both realism and liberalism have been updated to more modern versions (neoliberalism and neorealism) that represent a shift in emphasis from their traditional roots. Nevertheless, these perspectives can still be grouped into theory ‘families’ (or traditions). In your studies, you will need to unpack the various differences but, for now, understanding the core assumptions of each approach is the best way to get your bearings.

For example, if we think of the simple contrast of optimism and pessimism we can see a familial relationship in all branches of realism and liberalism. Liberals share an optimistic view of IR, believing that world order can be improved, with peace and progress gradually replacing war. They may not agree on the details, but this optimistic view generally unites them. Conversely, realists tend to dismiss optimism as a form of misplaced idealism and instead they arrive at a more pessimistic view. This is due to their focus on the centrality of the state and its need for security and survival in an anarchical system where it can only truly rely on itself. As a result, realists reach an array of accounts that describe IR as a system where war and conflict is common and periods of peace are merely times when states are preparing for future conflict.

Another point to keep in mind is that each of the overarching approaches in IR possesses a different perspective on the nature of the state. Both liberalism and realism consider the state to be the dominant actor in IR, although liberalism does add a role for non-state actors such as international organisations. Nevertheless, within both theories states themselves are typically regarded as possessing ultimate power. This includes the capacity to enforce decisions, such as declaring war on another nation, or conversely treaties that may bind states to certain agreements. In terms of liberalism, its proponents argue that organisations are valuable in assisting states in formulating decisions and helping to formalise cooperation that leads to peaceful outcomes. Realists on the other hand believe states partake in international organisations only when it is in their self-interest to do so. Many scholars have begun to reject these traditional theories over the past several decades because of their obsession with the state and the status quo.

The middle ground

The thinking of the English school is often viewed as a middle ground between liberal and realist theories. Its theory involves the idea of a society of states existing at the international level. Hedley Bull, one of the core figures of the English school, agreed with the traditional theories that the international system was anarchic. However, he insisted that this does not imply there are no norms (expected behaviours), thus claiming there is a societal aspect to international politics. In this sense, states form an ‘Anarchical Society’ (Bull 1977) where a type of order does exist, based on shared norms and behaviours. Due to its central premise, the English school is often characterised as having an international society approach to IR. This describes a world that is not quite realist and not quite liberal – but rather a world that has elements of both.

Constructivism is another theory commonly viewed as a middle ground, but this time between mainstream theories and the critical theories that we will explore later. It also has some familial links with the English school. Unlike scholars from other perspectives, constructivists highlight the importance of values and shared interests between individuals who interact on the global stage. Alexander Wendt, a prominent constructivist, described the relationship between agents (individuals) and structures (such as the state) as one in which structures not only constrain agents but also construct their identities and interests. His famous phrase ‘anarchy is what states make of it’ (Wendt 1992) sums this up well. Another way to explain this, and to explain the core of constructivism, is that the essence of international relations exists in the interactions between people. After all, states do not interact; it is agents of those states, such as politicians and diplomats, who interact. As those interacting on the world stage have accepted international anarchy as the defining principle, it has become part of our reality. However, if anarchy is what we make of it, then different states can perceive anarchy differently and the qualities of anarchy can even change over time. International anarchy could even be replaced with a different system if a critical mass of other individuals (and by proxy the states they represent) accepted the idea. To understand constructivism is to understand that ideas, or ‘norms’ as they are often called, have power. IR is, then, a never-ending journey of change chronicling the accumulation of the accepted norms of the past and the emerging norms of the future. As such, constructivists seek to study this process.

Critical theories

Critical approaches refer to a wide spectrum of theories that have been established in response to mainstream approaches in the field, mainly liberalism and realism. In a nutshell, critical theorists share one particular trait – they oppose commonly held assumptions in the field of IR that have been central since its establishment. Thus, altered circumstances call for new approaches that are better suited to understand, as well as question, the world we find ourselves in. Critical theories are valuable because they identify positions that have typically been ignored or overlooked within IR. They also provide a voice to individuals who have frequently been marginalised, particularly women and those from the Global South.

Marxism is a good place to start with critical theories. This approach is based upon the ideas of Karl Marx, who lived in the nineteenth century at the height of the industrial revolution. The term ‘Marxist’ refers to individuals who have adopted Marx’s views and believe that society is divided into two classes – the business class (the bourgeoisie) and the working class (the proletariat). The proletariat are at the mercy of the bourgeoisie who control their wages and therefore their standard of living. Marx hoped for an eventual end to the class society and overthrow of the bourgeoisie by the proletariat. Critical theorists who take a Marxist angle often argue that the internationalisation of the state as the standard operating principle of international relations has led to ordinary people around the globe becoming divided and alienated, instead of recognising what they all have in common as a global proletariat. For this to change, the legitimacy of the state must be questioned and ultimately dissolved. In that sense, emancipation from the state in some form is often part of the wider critical agenda.

Postcolonialism differs from Marxism by focusing on the inequality between nations or regions, as opposed to classes. The effects of colonialism are still felt in many regions of the world today as local populations continue to deal with the challenges created and left behind by the former colonial powers. Postcolonialism’s origins can be traced to the Cold War period when much activity in international relations centred around decolonisation and the ambition to undo the legacies of European imperialism. This approach acknowledges that politics is not limited to one area or region and that it is vital to include the voices of individuals from other parts of the world. Edward Said (1978) developed the prominent ‘Orientalist’ critique, describing how the Middle East and Asia were inaccurately depicted in the West. As a result, more focus within the discipline was placed on including the viewpoints of those from the Global South to ensure that Western scholars no longer spoke on their behalf. This created a deeper understanding of the political and social challenges faced by people living within these regions as well as an acknowledgement of how their issues could be better addressed. Postcolonial scholars are, therefore, important contributors to the field as they widen the focus of enquiry beyond IR’s traditionally ‘Western’ mindset.

Another theory that exposes the inequality inherent in international relations is feminism. Feminism entered the field in the 1980s as part of the emerging critical movement. It focused on explaining why so few women seemed to be in positions of power and examining the implications of this on how global politics was structured. You only need look at a visual of any meeting of world leaders to see how it appears to be a man’s world. Recognising this introduces a ‘gendered’ reading of IR, where we place an issue such as gender as the prime object in focus. If it is a man’s world, what does that mean? What exactly is masculinity as a gender and how has it imposed itself on international relations? As V. Spike Peterson (1992) argues, as long as gender remains ‘invisible’ it may be unclear what ‘taking gender seriously’ means. Once it is recognised that gender is essentially a social construction permeating all aspects of society, the challenges it presents can be better confronted in a way that benefits all individuals. Here, you might be beginning to see some overlaps – with constructivism for example. We are doing our best to present each approach separately so that you have a clearer starting point, but it is wise to caution you that IR theory is a dense and complex web and not always clearly defined. Keep this in mind as you read on, and as your studies develop.

The most controversial of the critical theories is poststructuralism. It is an approach that questions the very beliefs we have all come to know and feel as being ‘real’. Poststructuralism questions the dominant narratives that have been widely accepted by mainstream theories. For instance, liberals and realists both accept the idea of the state and for the most part take it for granted. Such assumptions are foundational ‘truths’ on which those traditional theories rest – becoming ‘structures’ that they build their account of reality around. So, although these two theoretical perspectives may differ in some respect in regards to their overall worldviews, they share a general understanding of the world. Neither theory seeks to challenge the existence of the state. They simply count it as part of their reality. Poststructuralism seeks to question these commonly held assumptions of reality that are taken for granted, such as the state – but also more widely the nature of power. Jacques Derrida’s contribution in this area was in how he showed that you could deconstruct language to identify deeper, or alternative, meanings behind texts. If you can deconstruct language (expose its hidden meanings and the power it has), then you can do the same with fundamental ideas that shape international relations – such as the state. By introducing doubt over why the state exists – and who it exists for – poststructuralists can ask questions about central components of our political world that traditional theories would rather avoid. If you can shake the foundations of a structure, be that a word or an idea, you can move beyond it in your thinking and become free of the power it has over you. This approach introduces doubt to the reality we assume to share and exposes the often thin foundations that some commonly held ‘truths’ stand upon.

Theory in practice: examining the United Nations

The United Nations (UN) is a highly respected international organisation created at the conclusion of the Second World War from the ashes of the League of Nations. Although it continues to exist, many doubt its claims to success. The United Nations General Assembly is an organ that provides every country with a seat at the table. However, the United Nations Security Council is where power ultimately resides. The Security Council has ten elected non-permanent members, each with their own vote. More importantly, the Security Council also contains five permanent members – the United States, Russia, China, France and the United Kingdom – reflecting the victors of the Second World War who stood dominant in 1945 as the United Nations was created. Any of those five permanent members can, through the use of a veto, stop any major resolution.

The United Nations does not possess complete power over states. In other words, it has limited authority to interfere in domestic concerns since one of its main purposes has generally been to mediate diplomatically when issues between countries arise. To better understand this last point, one can point to the challenges faced by the UN’s peacekeepers, who comprise civilian, police and military personnel positioned in areas of conflict to create conditions for lasting peace. Irrespective of any actual desire to maintain peace in a certain area, peacekeepers are typically only permitted to apply force in matters of self-defence. This draws on the common (though not always accurate) description of the United Nations as ‘peacekeeper’ rather than ‘peacemaker’. For these reasons, among others, it is possible to argue that the United Nations as an organisation is merely symbolic. At the same time, despite its limited ability to influence heads of state or prevent violence, it is also possible to argue that many nations have benefitted from its work. Aside from its mission to maintain peace and security, the United Nations is also committed to promoting sustainable development, protecting human rights, upholding international law, and delivering humanitarian aid around the world.

From a theoretical point of view, the effectiveness and utility of the United Nations differs depending on which perspective we choose to adopt. Liberals tend to have faith in the capacity of international organisations, primarily the United Nations, along with others organisations such as the International Monetary Fund, the World Health Organization and the World Bank, to uphold the framework of global governance. International organisations may not be perfect, but they help the world find alternatives to war through trade and diplomacy (among other things), which are staples of the liberal account of IR. On the other hand, middle-ground theories such as constructivism focus on ideas and interests. As constructivists focus often on the interactions of elite individuals, they see large organisations like the United Nations as places where they can study the emergence of new norms and examine the activities of those who are spreading new ideas.

Realists, although they do not reject the United Nations completely, argue that the world is anarchic and states will eventually resort to war despite the efforts of international organisations, which have little real authority. Generally, realists believe that international organisations appear to be successful when they are working in the interests of powerful states. But, if that condition is reversed and an organisation becomes an obstacle to national interests, then the equation may change. This line of enquiry is often used by realists to help explain why the League of Nations was unsuccessful – failing to allow for Germany and Japan’s expansionist desires in the 1930s. A contemporary example would be the United States invading Iraq in 2003 despite the Security Council declining to authorise it. The United States simply ignored the United Nations and went ahead, despite opposition. On the other hand, liberals would argue that without the United Nations, international relations would likely be even more chaotic – devoid of a respectable institution to oversee relations between states and hold bad behaviour to account. A constructivist would look at the very same example and say that while it is true that the United States ignored the United Nations and invaded Iraq, by doing so it violated the standard practices of international relations. The United States disregarded a ‘norm’ and even though there was no direct punishment, its behaviour was irregular and so would not be without consequence. Examining the difficulties the United States faced in its international relations following 2003 gives considerable weight to the constructivist and liberal viewpoints.

In contrast to liberals and constructivists, who value the United Nations to an extent, critical theories offer different perspectives. Marxists would argue that any international body, including the United Nations, works to promote the interests of the business class. After all, the United Nations is composed of (and was built by) states who are the chief protagonists in global capitalism – the very thing that Marxism is opposed to. Likewise, the United Nations can be said to be dominated by imperial (or neo-imperial) powers. Imperialism, according to Marxist doctrine, is the highest stage of capitalism. The United Nations, then, is not an organisation that offers any hope of real emancipation for citizens. Even though it may appear humanitarian, these actions are merely band-aids over a system of perpetual state-led exploitation that the United Nations legitimises.

Poststructuralists would seek to question the meanings behind the role of the United Nations and the arbitrary power structure of the Security Council. They would also look at how key terms are used by the United Nations and what they mean. For example, examining the wording of concepts like ‘peacekeepers’ and ‘peacekeeping’ as opposed to ‘peace-making’ and ‘peace-enforcing’. Or similarly, ‘collective security’ versus ‘international security’: poststructuralists would be sceptical as to whether these terms really differ in meaning and would point to the power of language in advancing the agenda of the United Nations – or perhaps that of the powerful states controlling it. Even the name of the dominant organ of the United Nations – the ‘Security’ Council – begs the question, security for whom? A critique here would point out that at its core, the United Nations is primarily concerned with facilitating the national security of powerful states rather than human security. In instances like these, the tools that poststructuralism provides to deconstruct and analyse wording have real value.

Feminists would look to how those in positions of power, whether politicians or those working for the United Nations such as officials and delegates, perpetuate a discourse of masculinity. Alternative feminine perspectives are still not adequately recognised and those in decision-making positions of power continue to be disproportionately male. Many countries that make up the United Nations marginalise the feminine voice domestically and thus perpetuate this at the international level. This is especially true of states where women hold more traditional roles in society and are therefore less likely to be considered suitable for what may be traditionally viewed as masculine roles, such as a delegate or ambassador.

Finally, postcolonialists would argue that the discourse perpetuated by the United Nations is one based on cultural, national or religious privilege. They would suggest, for instance, that, as it has no African or Latin American permanent members, the Security Council fails to represent the current state of the world. Postcolonialists would also point to the presence of former colonial powers on the Security Council and how their ability to veto proposals put forward by other countries perpetuates a form of continued indirect colonial exploitation of the Global South.

Hopefully, this brief reading of the United Nations from these varied perspectives has opened your eyes to the potential of IR theory as an analytical tool. We have barely scratched the surface, but it should be clear why so many divergent views are needed in IR and how, in a basic sense, they may be applied.


This chapter has surveyed the main approaches in IR theory, each of which possesses a legitimate, yet different, view of the world. It is important to note that the theories listed in this chapter are not exhaustive and there are many more that could be examined. However, this is a good starting point for achieving an overall understanding of the field and where the most common approaches are situated. Hopefully this has helped you consider your own theoretical inclination – or at least piqued your interest in determining where you might stand. It is not necessary to adopt one theory as your own. But it is important to understand the various theories as tools of analysis that you can apply in your studies. Using a theory to critique an issue, as this chapter did with the United Nations, is to understand the reason why these theories exist. Simply, they offer a means by which to attempt to understand a complex world. As international relations has grown in complexity, the family of theories that IR offers has grown in number. Due to its complexity and diversity, it is common for newcomers to have some difficulty in grasping IR theory, but this chapter should give you the confidence to get started.