The United States dollar seems to be under threat from multiple quarters. Countries that have been hit by American sanctions, such as Iran and Russia, economic rivals like China, and even allies in the European Union want to shake off the dollar’s tight grip on global finance.

For now, they are out of luck. The American economy and financial markets are the largest in the world, and there are no good alternatives.

In the long run, however, the rest of the world might get its wish. The dollar’s status as the dominant global reserve currency is the result of faith in America’s strong institutions. This includes the checks and balances among different arms of government, the rule of law and an independent central bank. These institutions have proved durable and earned the trust of global investors, who see the dollar as a safe haven in troubled times. But President Trump and his acolytes are undermining those very institutions with their words and actions.

Other countries have long chafed at the dollar’s dominance in global finance. Nearly two-thirds of the foreign exchange reserves held by the world’s central banks’, essentially their rainy-day funds, are held in dollars. It is the currency used to denominate and settle a significant part of international financial transactions. Almost all commodity contracts, including those for oil, are priced and settled in dollars.