A state – or other body, like a commune – is sovereign when it can decide its own affairs and make agreements with others. This sovereignty comes from the sovereignity of each one citizen (subsidiarity) – a basic political right, in developed democracies guaranteed by the constitution.
In representative democracies the mandate to execute this right on citizen's behalf is given to the representatives in elections for the duration of their mandate. In direct democracies, the citizens execute their sovereignty also by the right of initatives and referendums, which are binding for their representatives.
The EU was established as a co-operation among sovereign nation states, but has developed into a Union where the powers (competences) of the member states are limited. The EU has directly binding legislative powers, which do not have to be transformed into law
The EU can make binding international agreements. Viewed from the outside, this must make it look like a state, even though the EU does not have the formal representation in the United Nations of the member states.
Ultimately, the EU Court decides what part of national sovereignty can be reduced. Therefore, the member states are no longer fully sovereign.
Some argue that a country can gain more real influence by sharing formal sovereignty with other states. Others counter this by arguing that a country can lose real influence and democracy if it shares sovereignty in areas it could cope with just as well, or maybe even better, on its own.
The future
The EU Constitution proposes that a member state can regain full sovereignty by leaving the EU. In such cases states may, for example, have a partnership agreement instead. However, the country may be in danger of merely photocopying many of the decisions of the EU members. This is not genuine sovereignty, therefore the terms formal and real sovereignty are also used.Sovereign states may also negotiate bilateral agreements with the EU, like e.g. Switzerland.
Links
See also Federalism, Confederation, Initiative, Referendum, Political rights, subsidiarity, bilateral agreements.