When it is working properly, this structure balances the independence of nations and their economic interdependence that is at the heart of EMU. It should represent an approach where sovereignty is shared, meaning that it is neither exclusively national nor exclusively European. When EMU was first established, many people asked how monetary union could function effectively in a Europe of sovereign states.
The answer is that it can function effectively with an appropriate economic union. Not necessarily an economic union with a single fiscal authority. Not necessarily an economic union that presupposes an achieved political federation. But an economic union in which national policies are set within agreed limits and are subject to rigorous and effective mutual surveillance.