From the start of the Euro zone, the great danger of instability that threatens a single currency area was pointed out, if no explicit transfers were possible when an asymmetric shock occurs, that hits one country more than the rest of the members. The crisis in which the European project has been involved for years (like the rejection of the European Constitution) makes the further development of its economic structure politically impossible. But like a boomerang, this could turn itself against us in the coming years.