Hegemonic stability theory (HST) is a theory of international relations. Rooted in research from the fields of political science, economics, and history, HST indicates that the international system is more likely to remain stable when a single nation-state is the dominant world power, or hegemon.[1] Thus, the fall of an existing hegemon or the state of no hegemon diminishes the stability of the international system. When a hegemon exercises leadership, either through diplomacy, coercion, or persuasion, it is actually deploying its "preponderance of power." This is called hegemony, which refers to a state's ability to "single-handedly dominate the rules and arrangements ...[of] international political and economic relations.