From Imperial Hubris by Michael Scheuer:
‘The answer, I believe, lies in another point made by Robert Baer. “I knew enough about the way Washington worked to know that when it did not like some piece of information it did everything in its power to discredit the messenger,” he wrote in “See No Evil”.
‘Having spent twenty-two years in the U.S. intelligence community, I can confidently say Mr. Baer is absolutely correct, but that the problem is far greater and more pervasive than he suggests. To obscure threats they do not want to act against; to preserve the false facade of “seamless” intelligence-community cooperation and disguise the incompetence and dereliction of some agencies; to avoid national security debates that would need to focus on such politcally sensitive issues as religion, Israel, and Saudi perfidy, and — most of all — to avoid taking risks that could limit careers, post-government employment, or political aspirations; many U.S. intelligence community leaders ensured that most officers who recognized the extent of the threat bin Laden posed before 11 September 2001 were banished to language training, jobs entailing no bin Laden-related work, or excluded from meetings that might afford a chance to present intelligence honestly.’