To try to make sense of the last twelve months, and more, it is important to understand the variety of theories that seek to explain events, decisions, and outlooks. There are several schools of thought in the study of International Relations. All of them are valid to one degree or another when studying any particular situation or forecasting likely future scenarios. None necessarily dominates in any situation, rather they combine to form a mosaic that gives us a better understanding of what is happening and what will likely occur.
Main Theories
The first theory to consider is that of Realism, of which Machiavelli was perhaps the most well-known proponent. This holds that states are the primary actors, and their quest for both power and security is driven both by their national interest and their state’s survival. Importantly, Realism tends to see power primarily as military, attributing no real significance to softer forms of power. Realism was a core component of how the Great Game played out between the then major powers of Great Britain and Russia in the 19th century. Elements of Realist thought are now, once again, clearly evident in the foreign policy of President Trump’s administration, as we explain in our article The Great Game is Back, and his administration’s focus on hard power alone, and the discarding of soft power, is explained in The Power of Nations.
Next, we have Liberalism (once Idealism), which pursues international cooperation, democracy, global/ international institutions, and trade as mechanisms to both ensure continued peace and promote prosperity. Emmanuel Kant is perhaps the most well-known proponent of this school of thought, and it clearly dominated the post-WW2 Western world’s outlook. In our article When Institutions Become Optional you can see how the structures of the Liberalist world are being disregarded by the USA’s new Realist stance.
Constructivism puts forth that shared ideas, norms, identities and discussion shape our international relations reality meaning that, rather than there being an anarchic environment in which states compete in a Realist style, they operate within a values-based framework that provides rules and limits. Alexander Wendt is founding figure for this school of thought. Canadian Prime Minister Mark Carney’s speech at Davos in January 2026 drew heavily from Constructivist thinking. And, as we argue in our article Requiem Colossus, by casting aside the Constructivist (and Liberalist) structures and values of the post-WW2 order, the USA has surrendered its position as the world’s foremost authority.
Additional Schools of Thought
After the above three main schools of thought there are numerous others, all with insight and value to offer. Materialism, very well explained in Tim Marshall’s book Prisoners of Geography, contends that the decisions and actions of states are consciously and subconsciously shaped by their geography. We provide a clear explanation of the Materialist influences on the Russian psyche in our piece Russia Has Not Changed The World. Other real-time examples of Materialism can be seen, for example, in China’s Belt and Road Initiative.
Neorealism, or Modern Realism, is a sub-theory to Realism, which essentially goes directly against both the Liberalist and Constructivist schools by purporting that because there is no common, centralized authority on the planet that can set, maintain and enforce rules, there is indeed anarchy and this forces states to pursue increasingly powerful weaponry to protect their interests and guarantee survival. Importantly, however, in contrast to traditional Realism, Neorealism contends that power is not solely comprised of traditional military resources, but also the wider capabilities of a state. Again, read The Power of Nations to understand the aspects of soft power that the USA is relinquishing in its move towards Realism proper.
Other theories include Marxism and Neo-Marxism which surround economic class struggles and are inherently anti-capitalist. Post-Liberalism contends that states are forced to collaborate to ensure their own security and sovereignty. Postcolonialism encourages us to consider the effect that the colonialist era continues to have on geopolitics. Critical Theory seeks to challenge existing status quos. Feminism considers the influence of gender on international relations and questions the traditionally male-dominated structures of power. Complex Interdependence directly challenges Neo-Realism by asserting that there are instead numerous forces and reasons that connect societies and states, meaning there is no anarchy. There are also schools of thought that advance psychological considerations in International Relations theory, such as Emotional Choice Theory where cognition, misperception, need for identity, and emotional influences had impacts on the choices made by key actors in international relations events.
Conclusion
As you can see, practically all of these theories have some relevance, to a larger or lesser extent, in the events of the last twelve months or more – one actor or another has displayed one of the above outlooks or another. President Trump has displayed clear symptoms of Emotional Choice Theory and, we argue, woeful misperception or lack of cognition. His administration’s outlook displays clear Realist bent, and his focus on hard power alone shows it is not Neo-Realist. Meanwhile, Canadian and European actors are clearly adhering to elements of Liberalist, Constructivist, Post-Liberalist, and Complex Interdependence thinking. Where once a particular school of thought was more dominant, we’re now seeing a situation where several large blocs or powers are displaying considerably different outlooks – and those outlooks are clashing.