Not everyone wants to join single currency. Recent debates at the European Council and those of the European Parliament have carefully avoided taking a stance on the sensitive issue of a two-speed Europe. And yet, this is a matter that has to be tackled, as the gap between the countries of the eurozone and those that do not wish to participate or which do not meet the conditions for doing so continues to grow wider. The eurozone is increasingly self-contained. Its very nature implies and...