Producer: Owen Fay

When George W Bush began the 'war on terror', he focused the world's attention towards Afghanistan, al-Qaeda and Iraq, but not towards Saudi Arabia, even though 15 of the 19 hijackers on 9/11 were Saudi.

"There is clear evidence that the Bush administration and President Bush personally did not want the hardest part, the clearest part of the information gathered, indicating Saudi involvement in 9/11, to come out," says Anthony Summers, the co-author of The Eleventh Day.

Source: Al Jazeera