Anarchy

The lack of a supreme authority in the international system of states. One of the central concepts in the realist theory of international relations is the concept of anarchy. Unlike its common usage in reference to chaos, in international relations, anarchy simply refers to the fact that within the international system of states, there is no governing power above the level of the state.

From this understanding of the international system as anarchy, realist theories of international relations understand state behavior as inherently competitive. States in the international system are continually vying for power and trying to ensure their survival because there is no higher authority that can be expected to help any individual state persevere. The idea that states can rely only on themselves for security in the international system is known in realist theory as the principle of self-help. Self-help is the only form of help that can be relied on in an anarchic system.

Although the modern system of states is supplemented by many suprastate institutions such as the United Nations, realists contend that anarchy still defines the international system of states. Because the authority of a suprastate institution is limited, it depends on the cooperation of states to engage in military action, and certain powerful states (such as the United States) have the ability to supersede the decisions of the United Nations. These factors suggest that the United Nations is, in fact, not a true authority above the level of the state.