New Delhi, Oct. 22 -- The US dollar is under scrutiny from investors around the world. Banks, firms and governments that rely on it as an international means of payment and store of value worry about the policies of an erratic and hostile "America First" president. They fear further steps to weaponize the American currency. They fret that US government debt is on an unsustainable path and that the Federal Reserve, whose independence hangs in the balance, will feel pressure to inflate away those obligations.

The dollar may be the dominant global currency for the moment, but there are real questions about how long this moment will last.

And now to the rescue come-wait for it-dollar-linked stablecoins, blockchain-based digital tokens pegge...