America’s economic empire began in 1945, when the U.S. dollar was made partially redeemable in gold. Because foreign governments could convert dollars to gold, the U.S. dollar became the international reserve currency. (America had accumulated great stores of gold during the war.)
Unfortunately, America issued too many dollars, meaning our reserves of gold insufficiently covered our circulating currency.
By 1971, increased demand for gold caused the U.S. government to default. The news at the time spoke of breaking the link between gold and dollar. But the severing of links causes severe reactions. Default actually meant that the U.S. government went bankrupt.
The American empire then more blatantly forced the rest of the world to accept depreciating dollars. Wealth was being exchanged for depreciating fiat money.
Finally, the U.S. arranged for a better solution. During 1972-1973, the U.S. arranged for the Saudi government to accept only U.S. dollars for oil, which forced all OPEC members to follow suit, in exchange for U.S. support for the rule of the House of Saud.
Because the world needed more and more oil, the demand for dollars continually increased. The U.S. dollar, in effect, became backed by oil instead of gold.
When Saddam Hussein threatened to sell oil for euros, he had to go. When Iran began to speak of a new oil exchange, which would accept different currencies, it was placed on our enemies list.
Forcing countries to accept depreciating dollars is another way for an empire to tax other countries.