The Bretton Woods dollar-gold exchange standard began to unravel with the collapse of the gold pool in March 1968 and collapsed completely in August 1971, when Nixon formally ended the convertibility into gold of the U.S. dollar by foreign governments and central banks. The U.S. dollar, even dollars in the central banks or treasuries of foreign governments, was now a purely token currency and no longer a form of credit money. From now on, the dollar would follow the laws of token money, not credit money.
The question posed by Nixon’s August 1971 move was whether the U.S. dollar could maintain its position as the main world currency now that it was a token currency and not credit money. As long as the dollar had retained its convertibility into gold at a fixed rate by foreign central banks and treasuries—which also meant that the open market dollar price of gold could not move very far from the official $35 an ounce—commodity prices quoted in dollars and international debts denominated in dollars were in effect quoted and denominated in terms of definite quantities of gold.
But with the transformation of the dollar into token money, this was no longer true. The dollar no longer represented a fixed quantity of gold but a variable quantity. Its gold value could change drastically over a short period of time.