fédération

Fédération is a political arrangement in which several distinct political communities, often called states or provinces, join to form a single sovereign entity while maintaining a degree of internal autonomy. In a federation, sovereignty is constitutionally divided between the central government and the federated units. The exact distribution of powers is laid out in a constitution and can be difficult to change, often requiring both levels of government to approve amendments.

Key features include a central or federal government responsible for common affairs—such as national defense, foreign policy, and macroeconomic policy—and subnational governments handling local matters like education, health, and transport. Federations typically provide for representation of federated units in a national legislature, commonly through a second chamber with seats allocated to units, and sometimes via guaranteed equality of units in the upper house.

Federations differ from confederations, where the central authority is weaker and member states retain most sovereignty, and from unitary states, where central authority predominates and regional governments derive their powers from the central government. In practice, federations vary in practice: some rely on strong central powers and fiscal transfers; others grant wide provincial autonomy and have elaborate intergovernmental mechanisms to manage disputes and coordinate policy.

Famous examples include the United States, Canada, Germany, Australia, India, Switzerland, Brazil, and others. The term fédération is also used in Francophone contexts to denote similar structures, and the idea of federalism has been applied to regional unions and multinational states. Federations often face challenges such as intergovernmental friction, fiscal disparities, and constitutional amendments that require cross-level consensus.