This should explain it all.
It should also explain who has all the leverage. For those confused, JP Getty has a reminder: "If you owe the bank $100, that’s your problem. If you owe the bank $100 million, that’s the bank’s problem." Now just replace "$100" million with "€450 billion" (for now, likely to be €1 trillion in a few days), and "Spain" with "Germany", and it should all fall into place.