Until 1973 the US dollar was on a gold standard, but Richard Nixon took the US off the standard in 1973. Actually abandoned the system in order to print inflated currency called Greenbacks without any commodity backing.
Agreed, USD is backed by gold. Even with the oil backed countries the currency validation is done through the value of gold. Even now I'm not sure, but gold seems to be the backing commodity for USD along with its internal revenue.
Well mate in my own, 90% of what we use every day is produced by oil as the main source of power. If you are a country with oil, it means that you have sources, powers, and money to generate and keep it producing sources, income, and revenues.
I liked what he told about the dollar, gold, and bitcoin and it is very relevant. The reason why the US dollar has a nice value globally it is because the people who invented and support it are great salesmen, end of story.