Federal Systems. The United States and India with their state governments and Canada and China with their provincial governments are examples of workable federal systems in large nations with very diverse populations. Other federal states include Argentina, Australia, Brazil, Mexico, Nigeria, and Germany. The national governments of these countries are clearly more powerful than those of their subdivisions, even though the constitutions delegate many powers and responsibilities to the subnational units. In certain prescribed policy areas a state government may have a high degree of autonomy. In the United States, for example, state legislatures pass laws having to do with state affairs; state administrators carry them out; and state judiciaries interpret them.
Federal systems also include autonomous local governments such as county governments and municipal governments - in cities, boroughs, townships, and villages local governments may stand in a relationship to their state governments that corresponds to that of state governments with the national government. The citizens in each jurisdiction elect many of the public officials. In addition, certain special districts exist with a single function, such as education or sanitation, and have their own elected officials.
The layers of government in a federal system may not be clearly defined in practice. Often the different levels compete for control of functions and programs. In the United States and other countries the tendency over the years has been for the national government to become much more involved in areas that once were the exclusive domain of state or regional governments. In addition, the distribution of authority has become even more complex and varied with the rise of large metropolitan areas - the megalopolis - and the corresponding new local governmental organizations such as the Port Authority of New York and New Jersey.
Unitary States. In unitary states the national government performs all the governmental functions. Subnational national units administer matters within their jurisdiction, but their powers are set and delegated by the national authority. The national government retains the police power - the inherent power to provide for the health, safety, and welfare of its citizens. Taxation and major lawmaking powers also rest almost entirely with the national government.
Most nations are unitary states, but their institutions and processes may differ markedly. Great Britain, for example, is considered a unitary system, yet a certain degree of regional autonomy exists in Northern Ireland, Scotland, and Wales, and local county governments perform certain fairly autonomous functions. In France, however, strict control over the administrative territorial subdivisions is exercised by the national government. In other unitary states there exists only token territorial decentralization.
Confederations. Confederation produces the weakest central government. Member states in a confederation retain their sovereignty, delegating to the central government only those powers that are essential for its maintenance. The individual states jealously guard their power to tax and to make their own laws. The central government serves as a coordinating instrument to protect the interests of all its members. It also represents the confederation in dealings with outside governments, but its actions are subject to the review and approval of the confederated states.
The weakness of the confederate form of government led the United States to abandon that system in 1789 after only eight years. Confederations, however, have also served other nations - Germany and Switzerland, for example - as a preliminary step toward a more unified government. No modern nation-state is organized along confederate lines, yet some international organizations, such as the British Commonwealth of Nations, the European Union (formerly the European Community), and the North Atlantic Treaty Organization, have some aspects of a confederation.