The following letter was originally posted on a Saudi Arabian Web site previously used by al Qaeda to disseminate messages and was later published by the British newspaper The Observer. Its veracity has been doubted by some experts because the letter contains a series of issues never mentioned before in previous communications from bin Laden, such as AIDS and incest. The message cannot be fully authenticated as it does not have complementary audio or video. Whether or not it is from Osama bin Laden himself, it provides keen insight into the mind of the Islamist movement.

In the Name of Allah, the Most Gracious, the Most Merciful,

“Permission to fight (against disbelievers) is given to those (believers) who are fought against, because they have been wronged and surely, Allah is Able to give them (believers) victory” [Quran 22:39]

“Those who believe, fight in the Cause of Allah, and those who disbelieve, fight in the cause of Taghut (anything worshipped other than Allah e.g. Satan). So fight you against the friends of Satan; ever feeble is indeed the plot of Satan.” [Quran 4:76]

Some American writers have published articles under the title ‘On what basis are we fighting?’ These articles have generated a number of responses, some of which adhered to the truth and were based on Islamic Law, and others which have not. Here we wanted to outline the truth – as an explanation and warning – hoping for Allah's reward, seeking success and support from Him.