The Future World Order

Theories of international relations

Of the large range of theories that have emerged on how states get along with each other, or not as the case may be, I will draw, in simplified terms, on two leading schools today: liberalism and structural realism.

1. Liberalism
   The basic notion in liberalism is that conflict tends to occur where states have diverging interests. Where these interests are non-trivial, sometimes such conflict takes the form of war. […] What then makes it more or less likely that non-trivial disagreements will lead to conflict? Scholars in the liberalist tradition point to two specific mechanisms that enhance the chances of peace.
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   First, “democratic peace” exists where both sides of a conflict are functioning Western-style democracies. To put it differently, democracies do not fight each other. While the literature is rather vague about the mechanisms explaining this phenomenon (mutual respect?), empirically, this is probably as close to a law-like relationship as one can find in political science. Importantly, democracies are quite willing to fight non-democracies, though the statistics are skewed by the fact that the countries to have fought most wars – France, the U.K. and the U.S. – are in the democratic camp. One implication of this school of thought is that spreading democracy means spreading peace. This has been a basic tenet of U.S. foreign policy, at times with disastrous consequences (Iraq).
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   Second, “commercial peace” exists where both sides to a conflict are economically highly interdependent. The underlying notion is that both sides have so much at stake economically that it becomes too costly to settle conflict militarily. This is probably a weaker mechanism than democratic peace. The amounts at stake in mutual interdependence – say, through trade – are usually small relative to the size of the respective GDP levels. For instance, in the run-up to World War I, economic interdependence in Europe was actually very high, but the war broke out nonetheless.
2. Realism
   Realism looks back on a long intellectual history […] It remains the dominant paradigm of international politics today. The predictions of realism derive from its view of the international system as ultimately anarchic and based on self-help. In this view, there are no credible rules that prevent other, more powerful states from seizing weaker ones. While rules do seem to exist – for instance, in the shape of the United Nations – they are seen as derivative of the power of one or several states that can ensure compliance. Sometimes this works, as in the case of the first Iraq War. Often it does not.
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   This means states need to be concerned with securing their own survival against outside aggression. In realist logic, survival is likely if there is a balance of power: both sides of a possible conflict are equally strong. Under the crucial assumption of rationality, neither side will attack the other under these conditions. So survival requires building up a military strong enough to counter any threats – if necessary, with the help of allies – and an economy large enough to support the requisite military expenses.
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   In this paradigm, war becomes more likely when one side gains power relative to the other. In some cases, the gain of one side is matched by a build-up of the other side, which in turn prompts further investment in the military from the first. This is the classic arms race. In other cases, the declining side cannot keep up. It then has a range of options. It can try to find new allies to balance its rival. It can wage a pre-emptory war against its rival while it still has at least an outside chance of winning. Or it can just resign itself to the possibility that it will be conquered or dominated by its stronger rival. Regardless of the eventual outcome, a shift in the balance of power is dangerous.