
Gilpin 1981, Keohane 1984, Cox 1987, and Nye 2011 provide a useful conceptual discussion. The literature on hegemony is voluminous. Central questions to the debate are whether a hegemonic actor is well placed to shape the system, what strategies hegemonic powers use to define the system, if there are particular costs and benefits associated with exercising hegemonic influence, if other states gain or lose from hegemony, and under what conditions hegemonic powers endure. Some scholars also see hegemony as an institutionalized coalition of powerful and wealthy states.

The literature on hegemony tries to explain the United States’ role in the international system as a function of its privileged position within the system. Unipolarity refers to the distribution of military capabilities, whereas hegemony also refers to economic, social, and cultural power. Hegemony is distinct from Empire because a hegemonic power rules by influencing other states rather than by controlling them or their territory. However, it could also refer to the dominance of a cohesive political community with external decision-making power, such as the European Union. Usually this actor is understood to be a single state, such as Great Britain in the 19th century or the United States in the 20th and 21st century. In international relations, hegemony refers to the ability of an actor with overwhelming capability to shape the international system through both coercive and non-coercive means. Hegemony comes from the Greek word hēgemonía, which means leadership and rule.
