When the Central Intelligence Agency (CIA) failed to prevent the September 11, 2001 attacks, many asked whether more could have been done. But the true reason why the agency was blind to the signs may be a diversity problem, writes Matthew Syed.
The failure of the CIA to spot the warning signs of the 9/11 plot has become one of the most hotly contested issues in the history of intelligence. There have been commissions, reviews, internal investigations and more.
