New Delhi, Aug. 16 -- It keeps feeling like Groundhog Day. A Truth Social post insists the Strait of Hormuz is opening, Brent crude oil prices fall, nothing happens, oil prices rise. The wait continues.

The oil market's reaction to even the slightest hint of progress on negotiations to fully open the strait suggests that investors are attaching too much significance to what a diplomatic understanding between the U.S. and Iran can actually accomplish. Regardless of the details of any deal, large shares of the world's oil, gas, helium, aluminum, and fertilizers will remain at risk.

President Donald Trump, of course, wants to get out of this quagmire as fast as possible with something that still looks like success-if you tilt your head and...