International oil experts estimate that Iran is now warehousing as much as 40 million barrels — roughly two weeks of production — on the tankers. An additional 10 million barrels are in storage on shore.

“We are now forced to sell our most valuable export product in secret,” said Nader Karimi Joni, an Iranian journalist specializing in oil. “Iran had a great reputation; now we have to falsify bills of lading, hide the oil’s origin and store oil on ships.”