None of the examples of history, be they a federation of states or a union of nations, can serve as a blueprint for shaping political union. The EU has always been, and will remain, a unique undertaking for which there are no models that can easily be adopted.
Jürgen Stark: The IMF in a changing world (opening address) Opening address by Dr Jürgen Stark, Vice President of the Deutsche Bundesbank, at the Joint IMF-Bundesbank Symposium “The IMF in a changing world”, Frankfurt, 8 June 2005.