Can Donald Trump reopen the Strait of Hormuz?

On May 3rd Mr Trump said that America would help guide ships through the Strait of Hormuz, the vital waterway that has been mostly blocked since almost the start of the war. An average of just seven ships per day transited in the seven-day period until May 1st—unchanged from the week leading up to the ceasefire. What he called “Project Freedom” was due to begin on May 4th. The Pentagon says it has destroyers, warplanes and 15,000 troops ready to aid mariners.

In background briefings to reporters, however, the Trump administration admits it does not plan to provide naval escorts. Instead it will co-ordinate with vessels, advising them on the best route to avoid the mines Iran is thought to have laid in the strait, and perhaps stand ready to assist should they be attacked. In effect, America seems to be daring Iran to strike.

There are thus two reasons to think the scheme will have only a small effect on shipping. The first is that Iran also gets a say—and if it says the strait is still closed, most sailors will continue to avoid it, no matter how many American warships are nearby. Less than an hour before Mr Trump’s announcement, a tanker was reportedly struck off the coast of Fujairah in the United Arab Emirates. The details were not immediately clear, but Iran was almost certainly behind the attack.