My best (stupid) guess is weapons. US gov has a ton of weapons. Already sells tons of weapons. Now the prices will always remain stable. Other countries would love to know that 30 million usd would always be able to buy an f15. Other countries declaring war will increase the value of the USD, as buying weapons from us government will decrease amount of money in circulation.
Greed. The US dollar would catapult to the sky. Capitalism is the economic system based on greed. It has a built-in supply.
That is a terrible choice. You want to back currency with something scarce. I propose backing it with goodwill towards the US.
Currency needs to be backed by something other countries would want and actually hold. If nobody is holding a supply of it “backed” it would be pushing the currency value down.
On a more serious note, it should be something no single country has a majority of control over, and it shouldn’t be a limited resource, like gold which was previously used.
Trees? There I fixed global warming.
If every dollar printed meant the US planted a tree, then anytime a tree is cut down (even on private land) you have to turn in a dollar to be taken out of circulation, it technically would work.