The main concept of the so‐called English school of international relations, its central idea being that states can form a society by agreeing amongst themselves to establish common rules and institutions for the conduct of their relations and by recognizing their common interest in maintaining these arrangements. This idea goes back to Grotius. It is related to the contemporary American concept of regimes which also stresses the development of common norms, rules, and institutions among states as a way of regulating their relations. But whereas ‘regimes’ refers to specific instances of cooperation or coordination on particular issues, international society refers to what constitutes a system of states.
International society has states as its units, as opposed to world society, which is based on individuals and transnational actors. The exchange of sovereign recognitions establishes states as legal equals, and provides the basis for a shared identity as members of international society. It is sometimes argued that international society and world society are opposed ideas, with the state and national identity blocking the development of world society, and world society (especially human rights) undermining the identity and purpose of the nation‐state. But a case can be made that they are complements, with world society providing the political consensus to sustain the high levels of openness and interdependence of advanced international society, and international society providing the political framework for world society, so rescuing it from the fate of having either no political structure, or being dependent on an unattainable world government.
The most widely cited cases of international society are those of classical Greece and modern Europe. During their imperial heyday, the European powers imposed their own form of political order, the territorial state, onto the rest of the planet. This legacy provided the post‐colonial foundations for a global international society by making almost universal the mutual recognition of claims to sovereignty amongst all of the states in the system. It also raised the question of whether there can be a stable global international society in the absence of a global culture, and whether international society is necessarily global, or also operates at the regional level. The European Union is a good example of a highly developed regional international society. The contemporary global international society is unevenly developed, with some states sharing many more norms, rules, and institutions than others. At its centre lies a Western core, surrounded by concentric circles of states in each of which states share fewer of the norms, rules, and institutions as one moves further outward. A few rogue states are outside international society altogether.
By emphasizing the social bases for cooperation amongst states, and by seeing this as a natural outcome of relations in an anarchic international system, the idea of international society moderates the conflictual assumption about the nature of international relations associated with realism. It is a way of synthesizing many of the core elements of realist and liberal thinking, and it is vital to any understanding of rights and responsibilities concerning intervention by states into each other's affairs.