it is one thing for healthy nations to be the unfortunate victims of “contagion,” quite another for them to pick up the infection by embracing the diseased country. Which is what euro-zone countries have done. They have in effect welcomed the disease-weakened balance sheets of Greece and other countries onto their until-now healthy, stronger balance sheets, wiping out decades of good, prudent living in the case of Germany, and calling attention to thirty years of deficits, in the case of France.