Realism is a very old theory of international relations. Some realists trace its noble lineage back as far as Clausewitz and Bismarck; others reach back farther, to Machiavelli, or even to Thucydides. Indeed, some of the most self-assured realists claim that realism is based on truisms as old as human society itself.
Until relatively recently in human history, most people also emphatically believed that the world was flat and that the sun and the stars moved while the earth remained stationary. Only three hundred fifty years ago – more than a century after Machiavelli published The Prince – scholars rejected the mass of evidence that Galileo had collected to show that the earth revolved around the sun. His claim posed too great a challenge to beliefs as old as human society itself.
Realism survives for precisely the same reasons. Despite the mounting evidence that it inaccurately depicts international relations, staunch realists continue to reaffirm their faith in its universal validity.
Even the critics of realism – increasingly vocal over the past few decades – for the most part have not dared to challenge the central premises of realism, contenting themselves instead with merely tearing at the fringes of realist analysis. Instead of reconsidering the realist assumption that the international system is characterized by anarchy, or that the state must be the basic unit of analysis, critics of realism merely have pushed back a bit the narrow limits that the realist framework imposes on international cooperation.
Despite what staunch realists like Kenneth N. Waltz, John Mearsheimer, and Joseph M. Grieco say, the doctrine of realism was mortally wounded by the end of the Cold War, an event which realists neither predicted nor expected. It would be an act of compassion to put realism out of its misery...
Waltz distinguishes the realm of domestic politics from that of international politics, asserting that only the latter is characterized by anarchy. He states that domestic systems are "centralized and hierarchic," whereas international systems are "decentralized and anarchic."
Rules for behavior on the domestic level often are characterized by enforcement and adherence as spotty as rules for behavior on the international level. Many laws regulating individual behavior on the domestic level are not enforced. For example, many American states have laws against sodomy, and the U.S. Supreme Court has upheld their constitutionality. But these laws are almost never enforced. Similarly, many of the laws regulating individual behavior on the domestic level, although strictly enforced, are consistently broken with impunity by large numbers of individuals. The fact that a large proportion of motorists exceed the speed limit when no police cars are within view does not mean that highway travel is characterized by anarchy. Neither does the fact that speed limits on many highways have been raised after years of gross noncompliance with the law.
Domestic laws are often broken; they are not universally enforced; and they are often changed as shifts in the balance of power give rise to new governing coalitions. But no one would argue that, as a result, domestic politics is characterized by anarchy. Similarly, Waltz's argument regarding international anarchy holds little water.
But suppose we define an "international system" as any type of organized interactions of states. For instance, we could define the United Nations, the WTO, and the EU as "international systems." By following this approach, it becomes clear that international systems also vary widely with regard to centralization and hierarchicalness, ranging from the virtually nonexistent central authority in the pre-WTO GATT, to the more decisive and powerful (but rarely active) Security Council in the UN, to the more centralized, hierarchical, and decisive EU Council, Commission, and Court of Justice.
All political institutions can be ranged on a scale measuring their centralization of sovereignty. Weak international institutions, such as GATT, and confederations, such as the Commonwealth (or the confederation that preceded the U.S. Constitution, or the organization of Switzerland prior to 1848) are highly decentralized and assert very limited claims to sovereignty over the states that constitute them. Then come international institutions that are sovereign over individual states in specific policy areas, such as the EU and the WTO. Next come federations, such as Germany, Switzerland, and the U.S., the federal governments of which are sovereign over individual states in specifically enumerated policy areas, while the constituent states remain sovereign in remaining policy areas. Finally come states with centralized, unitary governments.
States are defined by the possession of sovereignty. But international institutions also possess a certain degree of sovereignty. The distinction that realists draw between states and international institutions merely is an arbitrary dividing line on the continuum of centralization of sovereignty. The international organization of sovereignty today, although arguably more distinct than during the era of feudalism, is hardly as clear-cut as the realists contend.
The organization of sovereignty within an individual state is also much more complex than traditional liberal analyses suggest. It is not enough to differentiate democracies from non-democracies, as Michael Doyle does; nor is it enough to differentiate monarchies, oligarchies, republics, and democracies, as did Aristotle and other Greek philosophers. As with the international organization of sovereignty, domestic organization is not a question of whether it is "this" or "that"; the question is where a particular case lies along the continuum that measures the degree to which sovereignty is centralized. The reality of international politics defies the simple assumption that if the sovereignty of an international organization is centralized enough, it becomes a state. How centralized must a confederation like the EU become before it crosses this hazy boundary?