The writer, Morgan Stanley Investment Management’s chief global strategist, is author of ‘Ten Rules of Successful Nations’

When the pandemic hit, the US dollar was as mighty as ever. Despite talk of faltering American supremacy, the dollar ruled as the medium of international trade, the anchor against which other nations value their currencies, and the “reserve currency” most central banks hold as savings.

Before the US, only five powers had enjoyed the coveted “reserve currency” status, going back to the mid-1400s: Portugal, then Spain, the Netherlands, France and Britain. Those reigns lasted 94 years on average. At the start of 2020, the dollar’s run had endured 100 years. That would have been reason to question how much longer it could continue, but for one caveat: the lack of a successor.