Iran has in effect closed the strait of Hormuz to oil and gas exports for the past four days with a mixture of drone strikes and fear that has halted commercial maritime traffic despite intense US attacks on Iran\u2019s navy.<\/p>\n
At least four tankers have been struck and Lloyd\u2019s List Intelligence reported that seaborne traffic had dropped by 80% on Sunday, with little sign of a return as key maritime insurers cancelled cover<\/a> the next day.<\/p>\n In an effort to ratchet up the threat, on Monday, Brig Gen Ebrahim Jabbari, a senior adviser to the commander-in-chief of Iran\u2019s revolution guards, said: \u201cWe will attack and set ablaze any ship attempting to cross.\u201d<\/p>\n How shipping slowed to a stop through the strait of Hormuz<\/a>How shipping slowed to a stop through the Strait of Hormuz<\/p>\n In fact the most recent reported incidents at sea were on Sunday, according to the UK\u2019s Maritime Trading Organisation. An unknown projectile exploded \u201cin very close proximity\u201d to a vessel 40 miles west of Sharjah in the UAE on 1 March, it said, though no serious casualties were reported.<\/p>\n Despite the rhetoric, Tehran\u2019s capacity to attack ships is likely to be sharply reduced. The US Central Command (Centcom) has engaged in a sustained campaign to target Iran\u2019s small navy, and said on Monday it had sunk or crippled all 11 of the ships the navy had operating in the Gulf of Oman to the east of the strait.<\/p>\n They include the Shahid Bagheri, a container ship converted over two years to carry, launch and recover drones and helicopters, and, in theory, a means of extending and projecting military power deep into the region, with Iranian officials saying it could remain at sea for 12 months with facilities such as a hospital on board.<\/p>\n Gen Dan Caine, the head of the US military, said in a briefing on Monday that the US attack on Iran began with strikes by Tomahawk cruise missiles which \u201cclosed in on Iranian naval forces\u201d and were accompanied by \u201cstrikes across the southern flank in Iran\u201d. Satellite imagery showed that Iran\u2019s Bandar Abbas naval base was heavily targeted.<\/p>\n Tankers off the coast of Fujairah in the UAE. Photograph: Amr Alfiky\/Reuters<\/p>\n While Israel has concentrated on attacking Tehran and politically important regime sites, a key part of the US military effort has been to secure the south of the country, controlling maritime routes and the airspace there.<\/p>\n The US military also said it has seen no sign of Iran escalating by attempting to mine the two-mile-wide shipping lanes with the help of its small fleet of submarines. Though details were scant, Centcom said it had targeted the Iranian submarine fleet, also at Bandar Abbas.<\/p>\n Nevertheless, tankers laden with oil, natural gas or other fossil fuel products have declined to risk the transit out of the Gulf, though there are reports that some are considering turning off their tracking transponders and risking a transit at night<\/a>, even though they may not be insured.<\/p>\n Conventionally, it is said, about a fifth of the world\u2019s crude oil passes through the strait of Hormuz. But that masks considerable regional and country variations \u2013 while countries in the Americas import 12.5% of their oil via the strait, the proportion rises to 45.7% for China, according to the data agency Kpler.<\/p>\n