In 1974, Henry Kissinger negotiated a deal where Saudi Arabia would sell its oil exclusively in U.S. dollars in exchange for U.S. security guarantees.

To buy oil in the Middle East, one needs to use US dollars, which is part of the petrodollar system.

In October 1973, the Arab members of OPEC, led by Saudi Arabia, declared an oil embargo against the United States, causing prices to quadruple.