|Part of the Politics series
|Basic forms of government
|List of countries by system of government
A unitary state is a sovereign state governed as a single entity in which the central government is the supreme authority. The central government may create or abolish administrative divisions (sub-national units). Such units exercise only the powers that the central government chooses to delegate. Although political power may be delegated through devolution to regional or local governments by statute, the central government may override the decisions of devolved governments, curtail their powers, or expand their powers. Unitary states in its modern concept originated in France, in the aftermath of the Hundred Years' War, national feelings that emerged from the war unified France. The Hundred Years' War accelerated the process of transforming France from a feudal monarchy to a unitary state. The French then later spread unitary states by conquests, throughout Europe during and after the Napoleonic Wars, and to the world through the vast French colonial empire. 
A unitary system of government can be considered to be the opposite of federalism. In federations, the provincial/regional governments share powers with the central government as equal actors through a written constitution, to which the consent of both is required to make amendments. This means that the sub-national units have a right to existence and powers that cannot be unilaterally changed by the central government. 
There are, however, similarities between federalism and devolution. Devolution within a unitary state, like federalism, may be symmetrical, with all sub-national units having the same powers and status, or asymmetric, with sub-national units varying in their powers and status. Many unitary states have no areas possessing a degree of autonomy.  In such countries, sub-national regions cannot decide their own laws. Examples are Romania, Ireland and Norway.
The United Kingdom of Great Britain and Northern Ireland is an example of a unitary state. Scotland, Wales and Northern Ireland have a degree of autonomous devolved power, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution. Similarly in Spain, the devolved powers are delegated through the central government.
The Taliban said Tuesday they plan to temporarily enact articles from Afghanistan's 1964 constitution that are 'not in conflict with Islamic Sharia (law)' to govern the country.
Afghanistan is a Constitutional Monarchy; an independent, unitary and indivisible state.