Donald Trump may have avoided the heavy snow that fell on the global business elite in Davos earlier this week, but he could not ignore the storm clouds building elsewhere in Europe.

Just as the American president was arriving in the Swiss mountains for the World Economic Forum on Thursday, Mario Draghi issued an extraordinary rebuke to the US. The European Central Bank president suggested that comments the previous day by Steven Mnuchin, Mr Trump’s treasury secretary, welcoming a weaker US dollar were a breach of agreements designed to prevent currency wars.

Mr Trump did his best to quell the controversy, insisting the US was still committed to a strong dollar. But the confusion increased the anxiety among other major economies about the bellicose and unpredictable direction of the US’s international economic policy.