Historians will one day note that September 24, 2018, was the Beginning of the End of the U.S. Dollar Hegemony.

I've been writing for years about how America's wars and sanctions have been driven Russia and China together, both politically and economically, and how they've been working to create a non-dollar financial system.
Earlier this year, most of the rest of Asia slipped out of the sphere of influence of the American Empire.
Just last month, Europe warned that it was losing patience with U.S. Dollar Hegemony.
Washington either didn't listen or didn't care.

Then this happened.

The European Union said Monday (Sep 24) its members would set up a payment system to allow oil companies and businesses to continue trading with Iran in a bid to evade sanctions after the US withdrew from a nuclear agreement.

Iran and the European Union announced their defiance towards US President Donald Trump's administration after high-level talks at the United Nations among the remaining members of the accord.

The WSJ says this "is a direct rebuke of President Trump’s policy on Iran and his decision to withdraw from the nuclear deal in May."
The details are still being worked out, and it's too late to save Iran from the full weight of our sanctions, but this is no short-term measure. It won't take long before Europe discovers that they can save a lot of money by using their own non-dollar SWIFT system. And they can save a bunch more money by trading in Euros instead of dollars.

Such transactions, presumably in euros and pounds sterling, would not be transparent to American authorities. European companies dealing with the state-owned intermediary technically might not even be in violation of the U.S. sanctions as currently written. The system would be likely be open to Russia and China as well.
Europe would thus provide an infrastructure for legal, secure sanctions-busting — and a guarantee that the transactions would not be reported to American regulators.
It would be pointless to sanction the special purpose vehicle because the U.S. would have no way of knowing who deals with it, and why.
...
No currency’s international dominance has lasted forever, and there’s no reason for the U.S. dollar to be the exception to this rule. Trump’s confidence in his ability to weaponize the dollar against adversaries and stubborn allies alike could eventually backfire for the U.S. as efforts to push the dollar off its pedestal grow ever more serious.