There was a palpable sense of discomfort at the latest G7 summit meeting in Ise-Shima, Japan. By the time the leaders of the world’s major developed economies meet again, there is no telling which of them will be populist insurgents. President Donald Trump could be representing the United States, or President Marine Le Pen could be representing France. They could be sitting down with British Prime Minister Boris Johnson, Italian Prime Minister Beppe Grillo, or even German Chancellor Frauke Petry. All of them would be championing nationalism and isolationism, in one form or another.