It seems to be that a currency is a commodity that most countries have to earn in order to use it. A better way to look at this is let's imagine a world where

It seems to be that a currency is a commodity that most countries have to earn in order to use it. A better way to look at this is let's imagine a world where copper was currency. Today, US copper has the following characteristics: - Most efficient electric conduction - Most widely available - Most widely accepted outside US - Fair and just producers Suddenly, a new CEO of US copper Inc comes in and says, we are losing coppers to other countries (disregarding that they bartered something for it). New CEO implements policies that reduce external supply of US copper. That changes the characteristic of US copper to: - Still most efficient electric conductor but only locally - Not as widely available outside the US - Slowly, causing US copper to not be as widely acceptable outside the US since there's no use for it outside US (vicious cycle of fewer people wanting US dollars and availability of dollars) - Unfair and unjust producers who use US copper as a threatening and bargaining chip, causing entire countries to starve. This is perhaps the biggest threat to that commodity being valuable. Would any buyer buy US copper if it risks their populace? Sterling used to be a major reserve a hundred years ago. Its colonialism and world wars went too far and it has eroded so much now. What makes anyone think the US will remain the same?