The RAF has Reaper drones flying over Iraq and Syria from nearby Kuwait which could be re-tasked if the decision is taken.
The RAF still has a number of Reaper drones based in nearby Kuwait - they are flying missions over Iraq and Syria but could be re-tasked if the decision is taken. The US already has surveillance aircraft operating above the Gulf and Australia is sending a P8 maritime patrol aircraft. They are part of a growing coalition being formed to protect shipping in the region.
It has also emerged that Iranian naval forces were interrogating commercial vessels in the days after the Stena Impero incident, specifically asking if they had British crew onboard. The practice, at its height in July, appears to have stopped now, but it was a chilling development and looked designed to drag the UK further into the crisis.
The senior British naval officer in the region said the situation is still tense.
Commodore Dean Bassett told Sky News: "The direct threat to those British merchant vessels still stands. We've seen nothing to suggest that Iran is going to abide by its international obligations."
And he wouldn't rule out the use of military force if necessary, saying: "While we call on Iran to abide by its international obligations, the Royal Navy - my sailors, my Marines and the ships under my command - are absolutely ready to protect and defend British merchant vessels in this theatre."