Sounds like a beef between the UK and Iran. The UK has 33,840 active personnel in the Royal Air Force, and 832 operational aircraft; and 86 ships, 174 aircraft and 33,280 personnel in the Royal Navy. I think they can handle this just fine without us.
If it’s a matter of sinking the Iranian navy and coming home on time for tea, the UK could do that easily. But war is very unpredictable, and the US might have to step in if the confrontation expands.
Best way out of this scenario is for Trump to send Green Berets and Seals into Akhwzistan to arm and train the oppressed Arabs there and encourage them to secede. There go the Iranian oil fields. There go Iran’s cash cow and war-making abilities.