who decides which ships can leave the straits of harmuz

Iran is the main actor deciding which ships can pass through the Strait of Hormuz when it is enforcing restrictions, often through its military and Revolutionary Guard forces. In recent reporting, Iran has said ships may need to coordinate with its military, while U.S. forces have also been shaping which vessels can move safely during the current tensions.

What that means

• The Strait of Hormuz is an international waterway, but in practice access can be limited by military control, mines, escorts, or blockades.

• Reports say Iran has allowed some vessels through and rejected or delayed others, especially when it wants leverage over rivals or to pressure negotiations.

• In the latest coverage, U.S. officials have also been clearing routes and escorting some ships, so decisions can depend on both Iranian restrictions and outside security arrangements.

Simple version

If you mean “who has the practical power right now?”, the answer is mostly Iran , backed by its military, though the U.S. and shipping firms also affect what can actually move.

TL;DR

Iran decides most of the passage rules in practice, but actual departures also depend on military escorts, mine clearance, and whether the route is deemed safe.