For years, policymakers have fretted about the global imbalances embodied in the US trade deficit and associated surpluses in China, Japan and oil-exporting countries. The fear was that if these were to unwind rapidly, with confidence evaporating in the US economy and the dollar, the outcome would be grim.

In 2006, the International Monetary Fund said a disorderly reduction in the US trade deficit would involve “a more rapid fall of the US dollar, volatile conditions in financial markets, rising protectionist pressures, and a significant hit to global output”.