But the effect has lasted so long only because, shortly before that, the European governments had agreed on banking union. The trust this indicated in the monetary union has helped the effect last until today.
But you received a lot of criticism shortly afterwards, particularly in Germany, when you announced the OMT programme, under which the ECB can theoretically purchase unlimited euro area government bonds under certain conditions. It was said that, in doing so, you would be carrying out monetary financing, which is prohibited.