Hegemonic stability theory (HST) is a theory of international relations. Based on study from the fields of political science, economics, and history, HST specifies that the international system is more likely to remain steady when a single nation-state is the leading world power, or hegemon.
Thus, the fall of an accessible hegemon or the state of no hegemon lessens the constancy of international system. When a hegemon implements leadership, either through diplomacy, coercion, or persuasion, it is in fact deploying its "preponderance of power." This is called hegemony, which refers to a state's skill to "single-handedly dominate the rules and arrangements ...[of] international political and financial associations.