Is the power of the dollar declining? While the Brics countries are openly putting forward the idea of creating a common currency, would the global network be ready to adopt a new international currency? This is what physicists have studied by analyzing the mathematical structure of commercial exchanges. It all began in 1944. The Bretton Woods agreements (United States) establish a new organization of the international monetary system, making it possible to decorrelate the value of state currencies from supply and demand. These agreements bind all currencies to the dollar through a fixed exchange rate, which becomes the only currency convertible into gold. But the abandonment of this system in 1971 did not prevent the greenback from remaining the reference currency.