in political science, intergovernmentalism treats states, and national governments in particular, as the primary actors in the integration process. Intergovernmentalist approaches claim to be able to explain both periods of radical change in the European Union because of converging governmental preferences and periods of inertia because of diverging national interests. Intergovernmentalism is distinguishable from realism and neorealism because of its recognition of the significance of institutionalisation in international politics and the impact of domestic politics upon governmental preferences.
The best-known example of regional integration is the European Union (EU), an economic and political intergovernmental organisation of 28 member states, all in Europe. The EU operates through a system of supranational independent institutions and intergovernmental negotiated decisions by the member states.Institutions of the EU include the European Commission, the Council of the European Union, the European Council, the Court of Justice of the European Union, the European Central Bank, the Court of Auditors, and the European Parliament. The European Parliament is elected every five years by EU citizens. The EU's de facto capital is Brussels.