President Trump’s announcement of tariffs on steel and aluminium was by no means unprecedented—Presidents Reagan and George W. Bush took similar actions. Yet it emphasises a reality that has become increasingly clear in recent years: the globalisation project, beloved of both classical economists and Davos Man big-government types, is falling apart. De-globalisation is here to stay and, contrary to Davos Man’s belief, it will be good for the world economy and for our living standards. The theoretical case for free trade, and to a lesser extent free movement of labour, is simple and clear-cut, first expounded by Adam Smith and…