Comment by majormajor

How does the "petrodollar" exactly prop up the US dollar? The price of a barrel of oil has oscillated quite a bit in dollar terms, so it's not like there's anything like a fixed or artificially-maintained 'exchange rate' there. There's, what, a 10x swing between highest and lowest USD price of oil in the last 10 years alone? The dollar has fluctuated vs other currencies too. I've never fully followed how trading for a dollar just to sell that dollar immediately for oil would only help the USD. It all gets turned into oil quickly, so wouldn't that mostly balance out in how demand for oil then relatively-weakens the dollar against the value of toil itself? The "medium of exchange" need has some effect, but I don't see it by itself driving "store of value." If there was a better store of value for the people selling the oil, what prevents them from swapping out those dollars essentially immediately? And then switch to taking payment in those other things as well?

And "just printing dollars" has well-documented inflationary effects inside the US too.