“Never let a crisis go to waste” has always been one of the European Union’s guiding principles. What about five simultaneous crises? Today, the EU faces what Frans Timmermans, the European commission vice-president, describes as a “multi-crisis”: Brexit, refugee flows, fiscal austerity, geopolitical threats from east and south, and “illiberal democracy” in central Europe. Rather than wasting its crises, the EU could be laid to waste by them. If so, Brexit will be the detonator…