It is time to retire the phrase: “When America sneezes, the rest of the world catches a cold.” Said to have first been used in relation to Napoleonic France, that idiom lost its value after Waterloo. Donald Trump is about to destroy its modern equivalent.

In foreign policy, the president’s choice no longer to be a reliable ally providing trusted security guarantees is a seismic change. It ensures that other countries will now be less willing to accept US demands. But it is on the economic front that hubris is most likely to result in humility for a country that has long since lost its status as the world’s largest producer of goods and services.

It is not just that Trump’s negotiating hand with tariffs is much weaker than he imagines. It is that the rest of the world controls 85 per cent of the global economy and no longer has to follow whatever the US does. Provided cool heads prevail in global commerce, the hotheads in the White House will not dominate the landscape. This century, America’s share of global goods imports has fallen from 19 per cent to 13 per cent, according to World Bank figures.