Suppose that a company in Peru wants to do business with a company in Malaysia. It should not be hard for the firms to make a deal. Sending money across national borders is generally straightforward, and so is the international transfer of large quantities of data.
But there’s a catch: whether or not the companies realize it, their transactions of both financial information and data will almost certainly be indirect and will probably pass through the United States or institutions over which the U.S. government has substantial control. When they do, Washington will have the power to monitor the exchange and, if desired, stop it in its tracks—to stop, in other words, the Peruvian company and the Malaysian company from doing business with each other. In fact, the United States could prevent many Peruvian and Malaysian companies from trading goods in general, largely cutting the countries off from the international economy.
Part of what undergirds this power is well known: much of the world’s trade is conducted in dollars. The dollar is one of the few currencies that almost all major banks will accept, and certainly the most widely used one. …