Global Britain is a catchy slogan. There is the delicious hint of recovered greatness – though this time not imperial but global. It also neatly deflects the charge that leaving the EU is rampant little Englandism; instead, it is the EU that is made to seem parochial and inward-looking. What’s more, it represents ambition. Global Britain will be a great power as we used to be – cutting trade deals with the world, sending our fleet east of Aden...