Why is the US threatening to blockade the Strait of Hormuz

A considerable number of ships may be needed to enforce the restrictions, according to Sidharth Kaushal, a naval power expert at the Royal United Services Institute, a defense and security think tank in London. "A lot depends on the early days of the blockade, how many vessels the Americans can seize, how much they can convince vessels attempting to slip through a cordon that they're likely to be seized," Kaushal said. "But in all likelihood, I'd say it will prove difficult for the U.S. to enforce."...Blockades historically haven't been enough on their own but have been used to exert pressure on other countries and their economies during conflicts, experts say. "There are always ways to economize, import, substitute, or just give up on certain things that you can no longer build for want of foreign inputs," Kaushal said. "It can make things a lot harder in a lot of ways, but it doesn't necessarily achieve decisive outcomes."