From the article:
Perhaps no one would be happier about that than President Donald Trump. Heres why: As Yale economist Robert Tiffin explained in the 1950s, if a countrys currency is the international reserve currency, then it has no choice but to run a current account deficit.
If a replacement is found, as the dollar replaced the British pound in the 1920s, it may be more likely to have trade surpluses which is what Trump has said he wants.
Was it really the 1920’s or was it post WWII? I don’t actually remember which it was. (regarding info in the article)