I lived and worked in Arabic lands for years and truly don't need
you to explain Islam to me!
Perhaps you yourself are unaware that “we have been here before” in our relationship with that faith. If you click
https://en.wikipedia.org/wiki/Muhammad_Ahmad you will be able to read all about the so-called Mad Mahdi in Sudan towards the end of the 19th century. The parallels with ISIS are remarkable. I particularly draw your attention to a sentence in the Political Heritage section of the Wiki report. It reads:
“Muhammed Ahmad's posthumous son, Abd al-Rahman al-Mahdi, became a leader of the neo-Mahdist movement in the Anglo-Egyptian Sudan who the British considered important as a moderate leader of the Mahdists.”
As you may see, even the messianic redeemer of Islam could be (quote) “a moderate leader”. So much for your oft-repeated claims that such people are immutable.
I hope in particular that the UK comes out of our current situation rather better than General Gordon and his army did in his!