Reuters
A source of currency market hand-wringing for decades, tales of the dollar's decline as the dominant world currency are nothing new. While the exchange rate of the greenback ebbs and flows with relative interest rate cycles - and it's surging again this year as the Federal Reserve hangs tough on its 'higher-for-longer' policy stance - the many theses surrounding a possible dollar sunset are more structural fears about America's standing. Lists of supposed threats over 30 years or more are long: the euro's arrival, yawning U.S. balance of payments gaps, the rise of China, the 2008 banking collapse and subsequent Fed money printing, and even the emergence of cryptocurrencies.