Here’s how it plays out: As the world’s dominant reserve currency, the dollar has no peer. International Monetary Fund data show that the greenback accounts for 63.3 percent of global foreign-exchange reserves, with the euro next at 20.3 percent, followed by the British pound and Japanese yen, both at 4.5 percent. That means that in times of crisis, the dollar benefits from global investors seeking a haven, even if the strife and the the uncertainty emanates from the U.S.

It’s possible that a trade war would drive flows into the dollar, putting upward pressure on the currency at the expense of other exchange rates. That would be on top of the natural demand for the greenback created by the anticipation of significant fiscal stimulus floated by the Trump administration and a faster pace of interest-rate increases by the Federal Reserve.