Nixon also broke the last link between the USD and gold reserves, and he had the Arab oil embargo, all of which helped weaken the dollar.

Now, an Arab oil embargo would have a significantly smaller effect on our internal market finished oil product prices, and we're so far away from a metallic-backed currency, it isn't funny, and the Fed has done their level best to devalue the USD with low yields and QE.

Much of where the USD sits is as a result of other currencies, and when the USD gets too weak, several of our trading partners (eg, Japan, the EU, Brazil) will deliberately weaken their own currencies. China, of course, maintains their peg.