International Relations Theory

International relations theory in nutshell

International Relations Theory (IRT), like other theories, is meant to provide a simplified view of a complex subject, thus enabling better understanding of it. At its best, theory identifies basic patterns of relations between actors (state or non-state) that take place over time and space. Theory claims to be apolitical but theorists cannot divorce themselves from their social, cultural or political background. Therefore, theory is always, some way or other, politically inclined.

For much of the twentieth century, IRT was dominated by two schools of thought – realism and liberalism. More recently, in the post-Cold War era, constructivism has become the third key approach of studying international relations.

Realism and Cold War

During the Cold War (1947-1990) superpower rivalry characterized the international system and had a profound impact on how analysts and policy-makers understood the fundamentals of international security. It is this background that realism became the dominant perspective in international relations. Consequently, the primacy of realism in the Western world of the 20th century was not just a reflection of the perceived reality but also the way policy-makers thought. Realism is generally recognized as the most competent research approach to great power relations.


Liberalism is a theoretical approach that rests on the assumption that all humans are rational beings and as such they are able to pursue their interests, understand moral principles and live according to the rule of law. Liberals value individual liberty above all and believe it is possible to achieve positive interactions and cooperative patterns between states. Cooperation is a central feature of all human activity, including international relations, where it is based on shared norms and values that build trust over time. States will be increasingly interdependent and cooperation is regulated through the democratic institutions and legal norms, which constitute central elements of international relations.

Constructivist approach

The basic view of this approach, which is not a single school of thought, is that international politics is socially constructed and shaped by different beliefs and cultures. As a result, neither material interests alone like realists suggest, nor institutions or values as liberalists allege, can explain state behavior completely. Constructivism focuses on the role of ideas in shaping our identities and the meaning we give to the world around us. In addition, the norms and rules shaping international relations can be constructed by international organizations and NGOs as much as by states and national values. In the constructivist paradigm, the things do not matter per se but they are made to matter by the nature of the interpretation placed upon them.