It has been and still is more difficult for other countries on account of their traditions and structures -- despite the obvious economic superiority of this concept. And the second realisation is that Maastricht is not merely the logical continuation of a historic trend. Monetary union is a quantum leap in qualitative terms.
We are daring to start anew what did not succeed in the 1970s. And this time it must succeed, and this success must be enduring. BIS Review 114/1997  - 11 -  Participation is final. Under the terms of the Treaty, there is no longer an escape hatch -- no matter what economic or political developments a given country may undergo.