The world has realised that it needs the EU to function and the euro not to go to the wall. This is the case just as much of the United States as China, and of the emerging countries, of Africa and of the Mediterranean countries. The political leaders of all these continents seem united in their agreement on the principle and are taking initiatives which take account of the situation. However, all economists - or nearly all of them - have their own theories and believe that they alone hold...