So that's official: the euro is a house of cards. The man who knows has confirmed all our worst fears.
It's very strange thing to say. Presumably Prodi does not want the euro to collapse but rather than assuring us it's very strong he's saying it's very weak and must be protected. So he's making it more likely rather than less that the euro will collapse.
That said, this blog thinks that Greece leaving would strengthen rather than weaken the euro. And if Spain, Portugal, Italy and Ireland also left the euro would get even stronger. The euro would achieve ultimate strength when only Germany is left using it.
Getting there would be traumatic though.