Why has International Relations been dominated by Realist ways of thinking about the international system since the end of the Second World War?

Since the end of the Second World War, Realist way of thinking have dominated the discussion about the interaction of actions on the international stage. Realism makes the following assumptions:

• States are the principle actors in the international system. All other actors are secondary.
• States are sovereign: there is no higher authority that can compel a state to act
• The behaviour of states is determined by the distribution of power across the international system
• Military force is the most important instrument of foreign policy a state has in it’s arsenal.

An IR theory is constructed from the observations of the international system, and the post-WW2 IR scholars arrived at the above conclusions from observing a world that had seen two global wars, a global recession, the rise of fascism and the spread of communism, which many postwar Western policymakers likened to fascism. This essay will begin by describing the basic ideas behind Realist theory, followed by a description of the pre-WW2 crises that contributed to this outlook, and finally with a look at the post-WW2 world of the Cold War that solidified Realism as the dominant tool with which to describe the international system.

The simplest way to introduce one to Realism is with the joke ‘a Realist walks into a bar and orders a half-empty glass of beer’. Both Realists and non-Realists would describe realism as pessimistic, though where non-Realists do so pejoratively, Realists embrace the pessimism. They see the world as being a free-for-all, where you have to be strong to survive. A Hobbesian war of all against all. To further utilise Hobbes, states act in the pursuit of their own self-preservation, which also can be called their nations interest, arming themselves to ensure they can defend themselves from the aggression of their neighbours. Realist thinking proposes that a state can never predict if one of it’s neighbours will become more militarily powerful then it, so it must always be prepared to bolster it’s own military. This is called a balance of power, where no one state is any more powerful that the rest, and is what Realists claim maintains global order, and that states should plan for the worst case scenario in the hope that the worst case would never arise.

This last point is important because Realism also claims that the distribution of power across the international system is what compels states to act, and that all states will act in the same way when put in a position of power over another. Accordingly, Realism says that states act to preserve their sovereignty because they can never truly trust their neighbours. A friendly neighbour today who later acquires more military power will eventually seek to coerce a weaker neighbour. Realism concludes that war is a natural state of international politics, and it’s from this conclusion that Realists constructed their theory of international relations.

The early twentieth century was marred with conflict: two global wars with a twenty year intermediate period characterised by three major crises that saw this period termed the Twenty Years Crisis. These crises were: the Japanese invasion of Manchuria in 1931; the Italian invasion of Abyssinia in 1935; and the involvement of Nazi Germany in the Spanish Civil War in 1936. The Treaty of Versailles at the end of the First World War saw the establishment of the League of Nations as a way for states to resolve their disputes without the use of military force and as a way of providing collective security without having to resort to forming alliances as had been the case before the war.

The League of Nations of nations attempted to impose punitive sanctions in all three of these crises and in all three cases was wholly ineffective. The League of Nations is a manifestation of the next most common theory of international relations, Liberalism, where interdependence is the principle force driving the behaviour of the actors. That the League failed to resolve these three major crises was seen later as a failure of the principle of interdependence and the possibility of finding diplomatic solutions to the worlds problems, and reinforcing the notion that states could only be compelled to act through coercion backed by the threat of military force.

After the Second World War, the world settled into a bipolar system with the USA and Capitalism on one side and the USSR and Socialism on the other. This system and it’s accompanying arms race, further reinforced Realist believes that the balance of power in the international system is what maintains order in the international system. The Realist belief that states are driven by deep power ambitions in pursuit of their national interest is evidenced in the attempts by the USA and USSR to exert their influence of over the newly emergent states in the Third World. Hans J. Morganthau believed this was a natural and permanent feature of international relations. Various local conflicts were forgotten across the world as states fell in on one side or the other.

The scholars who would become the Realist thinkers of the twentieth century arrived at their conclusions by observing the world’s recent history, and what they saw was grim. They saw Hobbes’ state of nature payed out on the international stage, as states were driven by man’s greedy pursuit of their own self-interest. Conflict has been a major recurring theme of early twentieth century history and attempts to resolve disputes diplomatically have failed spectacularly. The bipolar system of the Cold War and the subsequent balance of power the world sought to maintain reinforced Realism as the best way to describe the international system, leading to it’s dominance in IR discussion until the end of the Cold War.