Here’s how a U.S. naval blockade of the Strait of Hormuz could work. ‘This is a big task, and it’s a big gamble’

President Donald Trump announced Sunday that the U.S. Navy would immediately impose a blockade on the Strait of Hormuz after ceasefire talks with Iran failed to produce a deal.

That would turn the tables on the Islamic republic, which has effectively kept the narrow waterway closed with missile and drone strikes, keeping one-fifth of the world’s oil and liquid natural gas bottled up in the Persian Gulf.

At the same time as it’s been halting global supplies, Iran is letting its own oil exports through the strait, capitalizing on the massive spike in prices for crude.

But a U.S. blockade of Hormuz would cut off the financial windfall Tehran is reaping and further hobble an economy that was crashing even before the war started six weeks ago.

Retired Admiral James Stavridis, who previously served as NATO’s supreme allied commander, estimated that blockading the Strait of Hormuz would require two aircraft carrier strike groups that would provide air cover, plus a dozen destroyers and frigates operating outside the Persian Gulf.

Another half dozen U.S. warships as well as vessels from the UAE and Saudi navies would also be needed inside the Gulf, he told CNN on Sunday.

“So you try and bottle it up on both sides,” Stavridis added. “The bottom line: this is a big task, and it’s a big gamble.”

Just before the U.S. and Israel began bombing Iran,...