Three Iranian vessels tried to block a tanker passing through the Strait of Hormuz but backed off when confronted by a Royal Navy warship, the British government said on Thursday, raising the stakes in a test of nerves between Tehran and the West.
Britain urged Iran to “de-escalate the situation in the region" after the British Heritage oil tanker operated by BP was approached. The incident took place exactly a week after British Royal Marines seized an Iranian tanker, which London said was violating sanctions by bringing oil to Syria. “HMS Montrose was forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away," a UK government spokesman said in a statement.
Iran’s foreign minister Mohammad Javad Zarif dismissed as “worthless" the British allegation that Iran had sought to block the ship.
The incident followed US President Donald Trump’s warning he would soon “substantially" increase US sanctions on Iran as part of a drive to curb Iran’s nuclear programme and force Tehran to change its regional behaviour.
The US blames Iran for a series of attacks on shipping in the world’s most important oil artery since mid-May, accusations Tehran rejects but which have raised fears the long-time foes could slip into direct military conflict.
They came as close as ever last month, when Iran shot down a US drone and Trump ordered retaliatory air strikes, only to call them off minutes before impact. “I’d expect the Iranians to continue to seek opportunities to harass and obstruct without sliding into war," said Jon Alterman director of the Middle East Program at the Center for Strategic and International Studies think tank.
The US quit an agreement last year between Iran and world powers to curb Iran’s nuclear programme in return for granting it access to world trade. Washington sharply tightened sanctions against Iran since May with the aim of bringing its oil exports to zero. Iran responded by stepping up production of enriched uranium beyond limits in the nuclear deal.
Washington’s European allies disagreed with Trump’s decision to quit the nuclear pact and have tried to appear neutral. But Britain stepped into the crisis when it seized the Iranian tanker Grace 1 last week. Although European Union states have not followed Washington in imposing sanctions on Iran, they have sanctions in place that forbid selling oil to Iran’s ally Syria.
A senior Iranian military commander on Thursday said Britain and the US would regret detaining the vessel. Other Iranian officials have made similar statements, and some figures have been quoted as threatening to retaliate against British shipping.
US sanctions have effectively driven Iran from mainstream oil markets, depriving it of its main source of revenue and of the benefits it was meant to receive from its nuclear deal. Iran says it will return to full compliance with the agreement only if sanctions are lifted and Washington rejoins the pact.
BP chief executive Bob Dudley, asked about the situation in the Gulf at an event at London’s Chatham House on Wednesday evening, said: “We’ve got to be super careful about our ships."
An escalation in the Strait of Hormuz, the main outlet for Middle East oil traded around the globe, could drive up crude prices.Maritime security officials familiar with the matter said Britain was aiming to protect shipping lanes but there was no formal policy of escorting all UK ships through the area. The Montrose was there to ensure the safe passage of UK flagged ships when needed, they added.
Ship tracking information from data firm Refinitiv shows four other UK registered tankers now in the Gulf.
Bob Sanguinetti, chief executive with the UK Chamber of Shipping trade association, told Reuters the situation was tense and called for a de-escalation. “UK shipowners are in regular contact with the relevant authorities and agencies regarding the security situation in the region, and we are confident that the RN (Royal Navy) will provide the necessary support to their vessels," he said.
Oman, which hosts a joint British military base and shares the Strait of Hormuz with Iran, did not immediately comment. It has mediated between Tehran and the West and also allows the British and US navies to use its ports on the Arabian Sea.
The US is hoping to enlist allies in a military coalition to safeguard strategic waters off Iran and Yemen, marine general Joseph Dunford, the chairman of the Joint Chiefs of Staff, said on Tuesday.
Britain, France and Germany have sought to avoid being dragged into US sanctions but say Iran must return to full compliance with the 2015 nuclear deal they were instrumental in brokering. They have so far avoided triggering a dispute resolution process contained in the deal. Iran says it could take new steps in the next two months, including restarting dismantled centrifuges and purifying uranium to a sharply higher threshold, unless it is allow to resume normal oil sales.