That said (and to anticipate one of the later conclusions), the individual elements of the crisis are neither new, nor were they ignored beforehand. But the conjuncture of events produced outcomes that no-one forecast. And once the critical break had come, it was not possible to restore the status quo ante by fixing the individual elements that had gone wrong.
The ECB’s democratic mandate is laid down in the EU Treaties, which were ratified in all Member States according to their constitutional requirements. 1/3  BIS central bankers' speeches  Within this mandate, and to fulfil the euro-area wide objectives assigned to the ECB, the ECB has discretion to use its instruments as necessary.