Any country selling its goods abroad could price and collect payment for them in its own currency. Foreign purchasers would have to buy the sellers currency in the foreign exchange market (a whole nether story) in order to make such payments.
To communicate with each other they could also learn each other’s language. To communicate with everyone in their own language would require learning 7,000 languages. The economy of everyone adding English as a second language to their own is self-evident.
Rather than each trader dealing with several hundred currencies, there is huge economy in everyone dealing in one intermediary (so called vehicle) currency for pricing and payments of their cross-border transactions. But what currency?
When an exporter gives up pricing its products in the currency it pays its workers, it takes on a valuation risk. The choice of its invoicing currency and currency of payment needs to be attractive to potential buyers and of minimal risk to itself. The currency needs to have a relatively stable value for a large number of goods. The U.S. economy is large, and its goods are priced in dollars, which has a relatively good track record of price stability.
But to pay for imports with someone else’s currency the importer must have some of it. He must either take the risk of buying it in the foreign exchange market at whatever its current exchange rate might be or keeping some in reserve. Keeping a reserve of the international pricing and payment currency requires having safe assets with stable values in that currency, with deep and liquid markets in which they can be bought and sold. Currently the US dollar wins hands down. The Empire and the Dollar – Warren’s space (wcoats.blog)
The militarization of the dollar to serve U.S. foreign policy objectives increases the risk to others of holding and using dollars. How much that potentially undermines the dollar’s reserve currency status depends on how broadly the foreign policy objectives of the U.S. are shared and how well alternative currencies measure up to the value and market advantages of the dollar.
Warren's space 