The European Union must pull closer together and establish a strong military presence, so it can act as a “moral anchor” to the United States, the economist Kenneth Rogoff has warned. Speaking ahead of next week’s European elections, Mr. Rogoff, a former chief economist of the International Monetary Fund, said the EU should strive to become more “like a single country”. […] He added: “It would be a very good investment of German taxpayers’ money to write down debt in the periphery countries. There are a lot of ways to do it. You can be very opaque about it. The...