Federation

A federation (also called a federal state) is a union of partially self-governing provinces, states, or other regions under a federal government (federalism). In a federation, the self-governing status of the component units and the division of power between them and the central government are constitutionally entrenched and may not be altered unilaterally by either the central or constituent-unit authorities without following the constitutional amendment process. Sovereign power is formally divided between a central authority and a number of constituent regions so that each region retains some degree of control over its internal affairs. Some federal constitutions give the central authority exceptional powers that depart from the ordinary division of powers. In India, the Constitution requires the Union to protect states against internal disturbance and permits President's Rule when a state government cannot be carried on in accordance with the Constitution; it also authorizes Parliament to legislate for implementing treaties notwithstanding the ordinary federal allocation of legislative power. In Canada, section 91 of the Constitution Act, 1867 gives Parliament authority to make laws for the "Peace, Order, and good Government of Canada" in matters not assigned exclusively to the provinces. The Supreme Court of Canada has described the national-concern branch of this power as a rarely applied and strictly limited doctrine whose use must maintain provincial autonomy and the federal balance. The governmental or constitutional structure found in a federation is described as federalist, or as an example of federalism, and is commonly contrasted with the unitary state. France and Japan, for example, are unitary states. The Austrian Empire was a unitary state with crown lands; after the dissolution of Austria-Hungary, the Republic of Austria became a federation of Länder under the 1920 constitution. Germany, with its 16 states, or Länder, and Nigeria, with its 36 states and federal capital...