[david927]

You're right in some places, but it's more complex than that.

Yes, the USD is backed by the "full faith and credit" of the US government but the Petrodollar's global reserve status is fading. Saudi and Russia are both gearing up to trade oil to China in Yuan, for example. America's debt has passed 100% of its GDP and it has entered a period of high inflation. If the BRICS countries introduce a common PM-backed currency, it could present a better store of value than dollars and that could mean the end of the dollar's good run.

> gold is not linked to the existence of productive capacity

Industrial demand and investment demand are two different things. Silver has high industrial demand but that doesn't make it any better or worse a choice than gold for backing a currency.

> The best argument against it is that there is not enough gold

I'm not sure that's an argument against it. Also maybe it could be silver, or a basket which includes both.