The events unfolding in the Eurozone is the result of it being only a monetary union instead of a fiscal and monetary union. Milton Friedman predicted this would happen in '04.
First off, Friedman is not a doomsayer. Friedman correctly diagnosed the underlying causes of the Eurozone's malaise a decade ago. If the Eurozone entered into a fiscal union, much of the fundamental problems would be remedied. Political pressure/forgoing of sovereignty makes such an event highly improbable.