We all knew Donald Trump believes the security burden borne by America is unfair and that other countries have been ripping it off for years on trade and defence. It has been more surprising to find the re-elected president’s close aides also saying that the pre-eminent global role played by the US dollar is not the “exorbitant privilege” it was termed by Valéry Giscard d’Estaing as France’s finance minister in the 1960s, but an exorbitant burden. Now, one of the many huge questions about Trump’s second term is whether what Kenneth Rogoff calls “the Pax Dollar era” might be coming to an end.

A professor of economics at Harvard and former chief economist at the IMF, Rogoff is best known for This Time is Different, a fine book on financial booms and busts through the ages that he co-authored in 2009 with his colleague Carmen Reinhart. That work should by now have cemented its four-word title in investors’ minds as a sell signal whenever it is heard, though such is the power of wishful thinking that it probably hasn’t.

Rogoff’s new book, Our Dollar, Your Problem, also takes an historical approach to global finance, albeit over seven decades rather than eight centuries, and carries a timely warning. The sharp sell-off of US Treasury bonds following Trump’s April 2 announcement of America’s highest tariff wall for a century confirmed Rogoff’s view that the recently prevailing belief that real interest rates will be “l(fā)ower forever” is a dangerous myth. For he sees America’s, and hence the dollar’s, “Achilles heel”, as being the country’s $36tn stock of federal debt and the associated danger that a rising interest burden could lead it towards a fiscal crisis.