The simple answer to the question is that the Gold Standard prevents governments from printing their currency at will, which since the the inception of fiat currency, without similar controls, every single one has ended with their demise. Inflation, hyperinflation, poof!
Is the $US next? The concensus is yes. Having said that, "It won't go down without a protracted battle!" (A continuing example of that is how inflation figures are manipulated. Pulling food and energy a move demonstrationg how dumb the believe the "herd" is is only the tip of the iceberg!)
If and when the $US falls, will other fiat currencies fall with it? Again the concensus is yes.
Gold is fast becoming the "only" currency.
RUF