"why can't the USA go back to a dollar supported by silver or gold so as to save itself"
Because gold & silver are a store of value & it restricts the government on how big it can get & how much money they can spend. You can't print gold & silver, to fund government wars, it's a finite resource. On the other hand, you can print trillions of dollars just by entering a few digits on a computer screen & hitting the "enter" key, inflating your wealth away at the same time! Remember, global central banks want inflation, they want to destroy your wealth & prevent you from passing any wealth down to future generations.
