A British prime minister can order an airstrike, does that make him a monarch too?
But the people under him are technically sworn to the monarch - who ain't him. Which means they have the express position of saying "are you sure sir ?"
Also, since Cameron - parliament is in the loop at some point.
So no, the UK position is not that a rogue PM can order airstrikes and expect to be obeyed without question.
Up until now, I had naively assumed the US had similar safeguards. But if Trump is able to order an airstrike with no one in the chain of command to do their duty to the country then it seems I was wrong. Oh well.