First things first. We are not about to replay the 1930s. The world’s big economies are not deliberately indulging in “beggar thy neighbour” devaluations and protectionism is not poised for an ugly revival. As they say in the US: situation normal, all fouled up — or words to that effect.

Yet there are undertows we ignore at our risk. The US dollar is surging and export growth is slowing. The same applies to the widely forecast stampede of reshoring to the country, which is not really happening. Most US competitors are cutting interest rates and watching their currencies fall against the dollar. If these trends persist, and they will, US politics will react. A rising dollar is not the picnic it is made it out to be.

Yet it is hard to see what will stop it. The gap between North America’s growth, which is “solid”, in the words of Janet Yellen, US Fed chairman, and that of most other big economies is real. So, too, is the growing monetary divergence. US 10-year bond yields are historically low at just 1.7 per cent. But these are juicy compared to Germany (0.3 per cent), Japan (0.25 per cent) and even the UK (1.3 per cent). Investors will keep buying the dollar.