Shipping companies will decide when the Strait of Hormuz is truly open—not the U.S. or Iran—and the latest deal is already sowing confusion

Just days after the U.S. and Iran signed a memorandum of understanding to reopen the Strait of Hormuz, Tehran announced the critical waterway is closed again, threatening oil flows after they had barely started to rebound.

On Saturday, Iran’s military command said it closed the strait, citing continued Israeli attacks on Lebanon and U.S. “bad faith” in failing to uphold commitments to end the war. It also warned that “if the aggression continues, subsequent steps have been planned.”

Not to be outdone, President Donald Trump threatened to charge U.S. tolls for “services rendered as the Guardian Angel to the countries of the Middle East,” if a final deal with Iran isn’t reached in 60 days.

That came after the start of talks between the two countries had been delayed while both sides also sought to assert influence over the strait.

U.S. Central Command insisted safe passage through the strait remained intact and that traffic is up, with 55 merchant ships loaded with cargo and 17 million barrels of oil transiting on Saturday.

It added that U.S. forces are still operating in the area to support freedom of navigation and pointed out that the Joint Maritime Information Cente...