Any pivot away from the dollar by a top oil producer would represent a major threat to the currency’s supremacy.

The United Arab Emirates apparently dropped a hint the dollar’s dominance isn’t assured in the global oil trade if fallout from the Iran war gets worse.

To be sure, the UAE has plenty of money, including $270 billion in foreign-exchange reserves and trillions of dollars across its sovereign wealth funds.

If the Iran war triggers a deeper economic downturn, a swap line with the U.S. would provide the UAE’s central bank with a cheap supply of dollars that could back the dirham, which is pegged to the greenback, or beef up foreign-exchange reserves in the event liquidity runs low, the report said.

UAE officials also pointed out the U.S. started the Iran war and said they may be forced to use China’s yuan or other currencies for oil transactions if the availability of dollars gets tight, sources told the Journal.