The most urgent challenge for the European Union is the plight of its new member states in central and eastern Europe hit hardest by the economic crisis. Outside the safety net of the eurozone, several have faced the full force of speculation against their frail currencies. Hungary, Latvia and Romania had no choice but to run for emergency loans from the International Monetary Fund and Brussels institutions.

But what of those inside the eurozone that have got into fiscal disarray? For them, a bail-out is not an option: it is specifically banned by the treaty that set up the euro. In theory, at least, they are on their own.