Multilateralism is often defined in opposition to bilateralism and unilateralism. Strictly speaking, it indicates a form of cooperation between at least three States.
Nevertheless, this "quantitative" definition is not sufficient to capture the nature of multilateralism. Indeed, it is not simply a practice or a question of the number of actors involved. It involves adherence to a common political project based on the respect of a shared system of norms and values. In particular, multilateralism is based on founding principles such as consultation, inclusion and solidarity. Its operation is determined by collectively developed rules that ensure sustainable and effective cooperation. In particular, they guarantee all actors the same rights and obligations by applying themselves continuously (and not on a case-by-case basis, depending on the issue handled).
Multilateralism is therefore both a method of cooperation and a form of organization of the international system.
