Lying among a pile of papers at the hideout in Pakistan where Osama Bin Laden was shot dead was a carefully worded 21-page letter. It warned of the rise of a new and ruthless group of Islamic extremists capable of such extreme brutality that Al Qaeda should sever all links with them. In fact, it claimed the Islamic State of Iraq and Syria (or ISIS) had such complete disregard for civilian life that it could damage the reputation of Al Qaeda – if such a thing were possible for an organisation that has long traded in murderous terrorism. Scroll down for video
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21-page letter found at the Pakistan hideout where Bin Laden was killed
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Note said Islamic State of Iraq and Syria could damage Al Qaeda's reputation
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Memo documented acts of barbarism including bombing mosques
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ISIS, now called Islamic State, has control of area larger than Great Britain
To understand the threat Islamic State poses to the region, it first needs to be appreciated how it has grown into a force to rival @placeholder.