FOR THE respectable men running western Europe’s three biggest countries, misery is heaped upon misery. All are presiding over stagnant living standards and declining global influence. In Britain and France their rivals from the populist right are itching to take power (even the Alternative for Germany, or the AfD, may win a couple of state elections next year). And America, their key ally, has just accused them of hastening Europe towards what it calls “civilisational erasure”. Those three leaders also warn of a catastrophe—if the parties of the populist right should triumph. Friedrich Merz, Germany’s chancellor, describes his government as...