This process - which began as early as 1957 when the Treaty of Rome was signed - was difficult and not free from setbacks. I think that the high degree of convergence which had been reached in the euro countries before the single currency was introduced was important and necessary.
But in the end each country has to decide for itself what the “best way” is. The decision to adopt a single currency is inevitably a political one. Secondly, anyone considering any form of currency pegging and, even more, a monetary union must, above all, be fully aware of the consequences. Monetary union means relinquishing national sovereignty over internal and external monetary policy.