With its commitment to “break the vicious cycle between banks and sovereigns”, the European Council in June belatedly turned its attention to the real cause of the eurozone crisis: a lack of tools to deal with the unsustainable cross-border balances of private debt.

Since then, Germany has piled one misgiving on top of another about plans for a banking union to be drawn up by the end of the year. Some think this amounts to a “wrecking strategy” to scupper a pooling of risk and responsibility Berlin does not really want. That is unwarranted. Germany raises many valid points.

The June summit struck a bargain between creditor and debtor countries: possible pooling of bank recapitalisation in return for supranational bank supervision. Wolfgang Sch?uble, German finance minister, says the quality of a euro-wide supervisor takes priority over “unrealistic time expectations”. He is only half right. Saving the eurozone from a deep bank-driven downturn requires deliberation, but also haste. The sorry state of Europe’s banks was laid bare by this week’s International Monetary Fund warning of a possible $2.8tn credit crunch.