In a 2004 LRC post, How Stupid are Europeans?, I noted that unless an explicit right to secede or exit from the then-proposed European Constitution were added, any countries joining would likely be prevented by force from leaving later. Happily, the EU Constitution was never finally ratified, due to the heroic stubbornness of French and Dutch citizens. (However, many of its provisions were snuck into the Treaty of Lisbon in 2007.)
As noted in Greece Considers Exit from Euro Zone,
It remains unclear whether it would even be legally possible for Greece to depart from the euro zone. Legal experts believe it would also be necessary for the country to split from the European Union entirely in order to abandon the common currency. At the same time, it is questionable whether other members of the currency union would actually refuse to accept a unilateral exit from the euro zone by the government in Athens.
Never join a political union. Never centralize. It could be a one-way ratchet, as the CSA was forced to realize. Decentralization—and the Catholic idea of subsidiarity—is always to be pushed for, down to the individual level.
As I noted previously, after the lesson of the US Civil War–which is that if you want a right to secede from a “voluntary” union you better be VERY EXPLICIT—still, they have signed a draft EU Constitution that is not crystal-clear on this. True, Article 59 covers “Voluntary withdrawal from the Union”. It provides:
1. Any Member State may decide to withdraw from the European Union in accordance with its own constitutional requirements.
2. A Member State which decides to withdraw shall notify the European Council of its intention; the European Council shall examine that notification. In the light of the guidelines provided by the European Council, the Union shall negotiate and conclude an agreement with that State, setting out the arrangements for its withdrawal, taking account of the framework for its future relationship with the Union. That agreement shall be concluded on behalf of the Union by the Council of Ministers, acting by a qualified majority, after obtaining the consent of the European Parliament. The representative of the withdrawing Member State shall not participate in Council of Ministers or European Council discussions or decisions concerning it.
3. The Constitution shall cease to apply to the State in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the Member State concerned, decides to extend this period.
Note the bolded “weasel-word” language. If any rich state, say France, Germany, or Britain, tries to leave, a majority of poorer states could stop it by simply indefinitely “extending” the period that the EU Constitution applies to the State desiring to leave. As this article notes,
It was always the case that a member state could leave by simply repealing its own legislation [TELL IT TO SOUTH CAROLINA! –SK]. Now there is a formal procedure designed to show that the EU is a voluntary association. However a departing member would have to agree terms so there is an implied threat that it would not be that easy. This clause is presumably designed never to be used.
All I can say now is: I bet the UK is glad it never entered monetary union with the Euro; and Switzerland is glad it never entered the EU; and Germany is probably regretting it all!