Some of this information has been around for a while, but it is nonetheless shocking.
In this CBS article we find out that there was a direct and credible threat to (codename) 'Angel' or Air Force One on 9/11. So much so that Air Force One had to refrain from even telling their position on their radio to air-traffic controllers. This is a breathtaking revelation on its own, for it reveals that there was a very real fear that the terrorists could be listening in to the communications of Air Force One which seems to point to a fear that the 'terrorists' actually had moles planted on the inside. This is made more clear by claims in this article that the threat against Air Force One included secret codes only possible to be known by top level people in the military, intelligence or administration.
Webster Tarpley outlines this idea in the video below successfully. Even if you don't believe all of his assertions, it seems clear that just a bunch of frustrated islamofascists with boxcutters would not have been able to threaten Air Force One with top level codes, and as Tarpley even asserts, the nuclear launch codes.
World Net Daily in their article make an attempt to place the blame on Iraqi spies, but anyone who remembers the ridiculous image of the Information Minister of Iraq, Muhammed Saeed al-Sahaf during the Iraq invasion, can hardly believe that Iraqi intelligence was up to the task of cracking the nuclear launch codes of the U.S.