Will the European Union make it? The question would have sounded strange not long ago. Now even the project’s greatest cheerleaders talk of a continent facing a “Bermuda triangle” of debt, population decline and lower growth.

　　As well as those chronic problems, the EU face an acute crisis in its economic core, the 16 countries that use the single currency. Markets have lost faith that the euro zone’s economies, weaker or stronger, will one day converge thanks to the discipline of sharing a single currency, which denies uncompetitive members the quick fix of devaluation.

　　Yet the debate about how to save Europe’s single currency from disintegration is stuck. It is stuck because the euro zone’s dominant powers, France and Germany, agree on the need for greater harmonization within the euro zone, but disagree about what to harmonies.

　　Germany thinks the euro must be saved by stricter rules on borrow spending and competitiveness, barked by quasi-automatic sanctions for governments that do not obey. These might include threats to freeze EU funds for poorer regions and EU mega-projects and even the suspension of a country’s voting rights in EU ministerial councils. It insists that economic co-ordination should involve all 27 members of the EU club, among whom there is a small majority for free-market liberalism and economic rigour; in the inner core alone, Germany fears, a small majority favour French interference.