The plan, Aug. 15 -- Nine commodity vessels transited the Strait of Hormuz on Thursday. The number that usually does is twelve. The three vessels that didn't complete the passage are the measure of something Iran's parliament moved to institutionalize that same day: a formal strategic action plan granting legal cover to exclude vessels from countries it designates as hostile from the world's most consequential oil shipping lane.

reduced traffic through a waterway that normally handles roughly 20 percent of global oil supply - is already in evidence.

The IRGC Navy had supplied the operational declaration to go with it. Rear Admiral Ali Ozmaei put the position without qualification: "The Strait of Hormuz is closed. Our control over moveme...