“Trade makes the cake bigger so everyone can benefit.” So advised our distinguished visitor, British prime minister David Cameron, on the op-ed pages of the Wall Street Journal.

Well, not everyone—not the American worker who is displaced by exports, or the French film maker protected from competition by l’exception culturelle, or Europe’s farmers who can’t compete with America’s more efficient ones, or German manufacturers of solar panels who probably won’t survive even if the EU does slap a 68 percent tariff on Chinese imports. In short, the decision to extend free trade has losers as well as winners, the latter in this case the multinational companies that want restrictions on foreign investment in infrastructure relaxed, and consumers of the goods and services that might flow more freely across borders.