Originally It Was Because The Iranian Shah (King) Dared To Allow Iran To Take Control Of Iran's Oil Wealth In 1951.

https://news.sky.com/story/seven-charged-after-protest-outside-iranian-embassy-in-london-13387000

Rather like how Nasser dared to exert Egyptian control of Egypt's Suez Canal. Prompoting Ariel Sharon to lead Israeli commandos to invade Egypt. A deception intended to allow Britain to seize control of the Suez Canal under the guise of; "Peacekeeping."

The 1956 Suez Crisis which, ultimately, led to the downfall of UK Prime Minister Anthony Eden.

In the intervening, nearly, 80 years it's becoming self-fulfilling.

They want to attack Iran because generations of Ω's have been taught that they want to attack Iran.

https://www.youtube.com/watch?v=5gROA1iJK2k&pp (Him Of The Big Wheel(!), Massive Attack, Official Audio).