When modern people use the phrase “gold standard” they actually are referring to the concept known as “free gold" not any of the systems used before 1971. (Though many people lacking study of the topic may mistakenly be referring to pre-1971 systems.)
To quickly image how free gold would work imagine that Saudi Arabia no longer had any fear or respect for the USA or the dollar. Then they could simply announce to the world that any country trading with them who bought more from Saudi Arabia than they sold to Saudi Arabia would have to settle the trade imbalance in gold. This is the traditional function of gold: to extinguish debt, and especially between “Giants" such as Kings and Empires. Silver also served this purpose, but due to its abundance relative to gold, was commonly used by smaller players.
As international finance stands today, all fiat currencies are essentially derivatives of the dollar. This is an exorbitant privilege* that the USA has abused. Freed gold used to balance trade deficits would place a discipline on the dollar which the world is viewing in a more and more favorable light.
Freed gold could reach whatever fiat equivalent was neccesary to discipline all fiat currencies. There will never be a shortage of freed gold, only an eventual collapse of over-printed fiat necessary to encourage a holder of real money to let go of his gold in exchange for the “full face and credit” debt fiat currency represents.
It isn’t a coincidence that the two countries most capable of disrupting the military dominance the the USA are also the two countries that have recently built up huge gold reserves compared to the USA.