Abstract. The ordering principle of international relations varies widely across regional security complexes and has profound effects on regional order. States form hierarchies over one another based on relational authority, which itself rests on social contract theories that posit authority as an equilibrium of an exchange between a dominant state and the set of citizens who comprise the subordinate state. Regional orders emerge because of the strong positive externalities of social order and economies of scale in its production, and the mutually reinforcing legitimacy accorded the dominant state by local subordinates. This implies that regions characterised by the hierarchy of single dominant states will possess more peaceful regional orders. Regions often described as pluralistic security communities in which cooperation is understood to have emerged spontaneously from anarchy are better described as regional hierarchies in which peace and conflict regulation are the products of the authority of a dominant state.