Reversing Brexit

HOW should the European Union respond to the narrow decision by voters in the United Kingdom to leave? European leaders are now focusing, rightly, on how to prevent other countries from leaving the EU or the Euro. The most important country to be kept in the club is Italy, which faces a referendum in October that could pave the way for the anti-Euro Five Star Movement to take power.

Europe's fear of contagion is justified, because the "Brexit" referendum's outcome has transformed the politics of EU fragmentation. Before, advocates of leaving the EU or Euro could be ridiculed as fantasists or denounced as fascists (or ultra-leftists). This is no longer possible.

Brexit has turned "Leave" (whether the EU or the Euro) into a realistic option in every European country. Once Britain gives the Union formal notice (by invoking Article 50 of the Treaty of Lisbon), that option will enter the mainstream of political debate everywhere. Research by the European Council on Foreign Relations has found 34 anti-EU referendum demands in 18 other countries. Even if each of these challenges has only a 5 per cent chance of success, the probability of at leas…