Royal Navy Frigate Protects Tanker from Iranian Patrol Boats

The Royal Navy frigate HMS Montrose fended off an Iranian attempt to interfere with a British tanker in the Strait of Hormuz on Wednesday, according to the government of the UK. 

According to the UK Ministry of Defense, three Islamic Revolutionary Guard Corps boats approached the tanker British Heritage and attempted to impede her passage as she transited the strait. In response, 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." (U.S. officials put the number of IRGC boats involved in the encounter at five vessels, not three.) 

The IRGC said in a statement that it possesses the capability to seize a UK ship if so ordered, but it denied that the run-in with the British Heritage occurred. “In the past 24 hours there has been no encounter with foreign ships including English ships,” the service wrote in a statement. Iranian foreign minister Mohammad Javad Zarif told state media that the UK's version of events is "worthless" and designed to "cover up their weaknesses."

If the UK account is correct, it would fit with previous patterns of IRGC attack boat behavior in the strait. In years past, the U.S. Navy frequently encountered IRGC vessels approaching at close quarters during transits through the area.

The alleged incident involving the British Heritage would also align with warnings from top Iranian officials about "repercussions" for Britain's recent seizure of an Iranian-controlled tanker at Gibraltar. Royal Marines boarded and seized the VLCC Grace 1 near the Strait of Gibraltar on July 4, and two recent Iranian statements - one by a former IRGC commander and another by a former Iranian nuclear negotiator - discussed the possibility of an action targeting a British tanker in retaliation.

In a statement Thursday, UK defense secretary Penny Mordaunt expressed gratitude to the crew of the Montrose. “I would like to thank the Royal Navy for their professionalism, which upheld international law and supported freedom of navigation through a shipping channel that is vital to global trade,” she said. 

In a note to clients, maritime security consultancy Dryad Global assessed that the British account was the more likely of the two, and it suggested that future Iranian interference would likely be limited to symbolic actions. "It remains Dryad’s assessment that this latest attempt represents a credible ‘show of force’ by the Iranian regime and IRGC(N), which is designed to act as a tangible follow up to British involvement in the detention of the Grace I," Dryad wrote. "It would be highly unlikely for Iran to persist in any attempt to detain a vessel in international waters or to engage a vessel with weapons. Any action of this nature would significantly compromise ongoing Iranian diplomatic efforts as well as significantly increase the likelihood of direct military action against Iran." 

Captain of Iranian-controlled tanker charged

Authorities in Gibraltar have arrested the captain and the chief officer of the Grace 1 for allegedly attempting to violate EU sanctions on shipping oil to Syria. The arrest follows an extended search of the vessel, including the seizure of shipboard documents and electronic devices. "The investigation is still ongoing and the Grace 1 continues detained [sic]," police said in a statement.

The government of Gibraltar says that it seized the Grace 1 for allegedly carrying oil to a refinery operated by an EU-sanctioned Syrian entity, not for the vessel's connections to Iran. She is believed to be carrying Iranian oil in violation of the unilateral U.S. sanctions on Tehran's nuclear program.

Gibraltar said in a statement that it is acting on its own accord in regards to the Grace 1, and that "there has been no political request at any time from any government that the Gibraltar government should act or not act." The exclave is a British Overseas Territory, and under the terms of its 2007 constitution, it is not self-governing on matters of defense and foreign policy.