A currency safe haven is feeling less safe

London

IT IS the closest thing to a certainty in the global economy. When trouble flares and anxiety mounts, people who manage money traditionally entrust it to a seemingly indomitable refuge, the US dollar.

Yet on Wednesday, in the hours after US President Donald Trump's threat to unleash "fire and fury" on North Korea if it continued to menace the United States, global investors sold the US dollar. The same dynamic played out in June, as Saudi Arabia and other Arab nations imposed an embargo on Qatar, delivering a fraught crisis to the oil-rich Persian Gulf. And the US dollar dipped in July after Russian President Vladimir Putin expelled 755 US diplomats, ratcheting up tensions between the two nuclear powers.