In Europe, inflation varies among each country. Introducing a universal money system would change dramatically the ways of life for many people. A loaf of bread could cost a Eurodollar in Great Britain and ten Eurodollars in Portugal. The price of the Eurodollar in overseas exchange would be very low because no one would want to deal with the hassle of checking how much its worth is in Yugoslavia and how much its worth is in Russia. However since this version of European unification does not include any political decisions it would be easier to accept by the different nationalities in Europe than a total overhaul.
Humans are different from the other members of the animal kingdom for many reasons.
This creates much diversity among us. In Europe it will be this diversity in this time and the past that will prevent a unified Europe.