It’s the biggest mystery in global finance right now: Who conducted a sneak attack on the U.S. dollar this week?

It began with a thinly sourced but highly explosive report Monday in a British newspaper: Arab oil sheiks are conspiring with the Russians and Chinese to quit using the dollar to set the value of oil trades — a direct threat to the global supremacy of the greenback.

Is it true? Everyone from the head of the Saudi central bank to U.S. officials scrambled to undercut the story, but no matter.