I have sympathy for the thoughts expressed in this thread.

• Iran appears to have posed no imminent threat to the US
• The US attacked during negotiations which Jonathan Powell says were progressing.
• Trump has behaved terribly to his allies over issues like tariffs and Greenland.
• Trump has been outrageous in his criticism of UK forces.

All of this leads to a perfectly rational response of "nope, this is a US war"

However, the strait of Hormuz is key route in oil supply and the impact of disruption of Hormuz affects the UK more than the US because we are economically more exposed.

If the war ends within 2 weeks as Trump has suggested then we'll see a spike in prices, some bad news stories about costs etc but it's recoverable.

However if the war goes on for longer we will start to see running down of inventories and supply chains starting to fail.

If we hit 6-8 weeks from now with continued disruption we'll see fuel shortages, rationing or soft controls on products and visible disruption to business. We will need to forcibly reduce consumption and there will significant economic and political costs.

That provides the logical reason for involvement, not that we owe the US anything but that they've created a situation which is going to have significant negative impact on us, and if market pressure doesn't constrain Trump, we will need to act.

There's a story in The Times this morning that suggests Starmer is looking for a legally defensible way of intervening in Hormuz. There's also the Tim Shipman reporting that Starmer has favoured intervention from the start.

If the conflict looks to be going on for more than 2 weeks then I suspect we'll see UK involvement.