If a country ran into a liquidity problem, the US would provide the needed liquidity in USDs.

FORBES: Our Fiat Dollar Has Cost the United States $80 Trillion

However, after 1958, when the economies of other countries began to recover and the trade surpluses began to decline, they quickly accumulated USDs.

FORBES: Our Fiat Dollar Has Cost the United States $80 Trillion

This meant that countries holding USDs as reserve currency were under increasing pressure to convert their USDs into gold to protect their own positions.

FORBES: Our Fiat Dollar Has Cost the United States $80 Trillion