The European Central Bank was never likely to ride to the rescue of Italy and Spain. Instead Jean-Claude Trichet, president, on Thursday overrode opposition from Germany’s Bundesbank to send a different signal: that the euro’s monetary guardian would help governments if they took steps needed to tackle the eurozone’s debt crisis.

The ECB’s surprise decision to resume intervening in bond markets – but limit its action to buying Portuguese and Irish bonds – made clear to Rome and Madrid that it still thought they had to do more to bring public finances under control.

Along with other measures to boost liquidity in the eurozone financial system – including the reintroduction of unlimited six-month loans – it decision was part of what the ECB hoped would be a calibrated response to the crisis, which has this week turned dramatically for the worse.