The UK has announced it is joining forces with the United States in the Gulf to protect commercial ships transiting through the Strait of Hormuz.
Two Royal Navy warships, HMS Duncan and HMS Montrose, will work alongside two US destroyers to shield tankers as they pass through the contested waters.
The move marks a change of approach from that taken by Theresa May’s government, which tried to generate a European-led coalition.
Despite summits in Bahrain and Tampa in the past few weeks, no other countries have joined up so far.
This latest initiative – described by Defence Secretary Ben Wallace as a “new maritime security mission in the Gulf” – comes as the British-flagged ship the Stena Impero remains impounded by Iran, while its crew are still being held hostage onboard.
Iranian state television reported over the weekend that it had captured another commercial ship, although no details are known about it and it’s not believed to have a British connection.
Until now, HMS Montrose has accompanied 47 British flagged merchant vessels through the strait, and will soon head to port in Bahrain for repairs, leaving HMS Duncan as the sole British warship in the area.
Mr Wallace said the UK was “determined to ensure her shipping is protected from unlawful threats”.
He added: “Upholding international maritime law and freedom of passage is in all our interests. We are seeing, across our seas and oceans, too many incidents that seek to challenge such freedoms.”
The British announcement is being seen as a diplomatic move to bounce other countries into joining.
Germany has publicly dismissed calls for its participation, and despite having a frigate in the region, France is yet to commit.
Britain said it was “spear-heading” a new force, but in reality only two nations make up the coalition so far, and nothing significant changes in terms of command and control: the British ships will continue to take their orders from Permanent Joint Headquarters in Northwood.
The Foreign Office insists the overall UK approach to Iran and the nuclear deal hasn’t changed.
The British ships will not be asked to police American sanctions against Iran.
“It is vital to secure the freedom for all international shipping to navigate the Strait of Hormuz without delay, given the increased threat,” Foreign Secretary Dominic Raab said in a statement.
“This deployment will reinforce security and provide reassurance for shipping. Our aim is to build the broadest international support to uphold freedom of navigation in the region, as protected under international law.
“Our approach to Iran hasn’t changed. We remain committed to working with Iran and our international partners to de-escalate the situation and maintain the nuclear deal.”