Greenback Mountain

The numbers are stunning. Governments around the world hold nearly $5.5 trillion dollars in reserves—an amount greater than the gross national product of any country except the U.S. China has by far the largest horde, with over $1.3 trillion in the till and almost one-quarter of the world's total. But the rest of Asia is far from poor: Japan holds more than $900 billion, Taiwan and South Korea together own over $500 billion and India's reserves crossed $200 billion this year, up more than 30% from a year ago. About two-thirds of these reserves are denominated in dollars and about 60%...