Iran has a trick up its sleeve against the US blockade

 After high-stakes peace talks in Islamabad collapsed over the weekend, the future of a fragile ceasefire between the US and Iran now appears to rest on a 100-mile waterway between the Persian Gulf and Arabian Sea.

The United States imposed a blockade on Iranian ports and coastal areas east of the Strait of Hormuz, which came into effect at 3pm BST on Monday.

US Central Command warned that vessels will be subject to “interception, diversion and capture” regardless of their flag. More than 15 US warships are in place to support the operation, a senior official told The Wall Street Journal.

President Donald Trump threatened that ships sailing from Iranian ports would be subject to “the same system of kill that we use against the drug dealers on boats at Sea”, referring to the administration’s controversial attacks on boats off the coast of Venezuela.

Oil prices surged in response to the threats, but the US military insisted that the action would “not impede” the movement of ships carrying humanitarian goods, such as food, through the Strait of Hormuz.

A US-sanctioned Chinese tanker, the Rich Starry, appeared to sail straight through the Strait on Tuesday in apparent defiance of Mr Trump’s blockade. But it later made a U-turn in the Gulf, with US Central Command saying some merchant vessels had “complied with direction from US forces to turn around”.

What does Trump’s blockade involve?

In practice, President Trump’s blockade will impact vessels departing from Iran’s ports and coastline, regardless of their country of origin. The US has explicitly said it will not target vessels that aren’t linked to Iran or its ports, but those that are will be intercepted, diverted or captured.

However, the US leader has also ordered the navy to hunt down vessels that have paid Iran a transit toll, which includes Chinese tankers and Indian bulk carriers that are not parties to the conflict, according to Professor Barry Appleton, co-director for international law at New York Law School.

“You have a narrow, mine-threatened strait, active hostilities, and now the US Navy is being asked to police every vessel entering or leaving Iranian ports,” he told The Independent.

“That’s not a blockade. It is more akin to a traffic enforcement operation in the middle of a war zone.”

How has Iran prepared for the blockade?

Iran appears to have a number of tricks up its sleeve to circumvent the impacts of the blockade, including floating storage, shadow fleet tankers, and the use of alternative ports.

According to marine traffic data analysed by Kpler, five liquid tankers transited the Strait of Hormuz in the first two days of the blockade, for all categories – liquids, LNG, LPG, and dry bulk – a total of eight vessels crossed between 13 and 14 April.

On Tuesday, a further five vessels crossed the Strait, but it is important to note that the blockade is not within the Strait but further outside the Gulf of Oman. Kpler told The Independent that four tankers carrying Iranian crude are idling in the Gulf of Oman. One ship passed through on Wednesday.

“The objective is to constrain Iran’s ability to export crude and condensate, which could eventually lead to production shut-ins,” Kpler’s senior crude analyst Johannes Rauball told The Independent.