Former CIA Director George Tenet wrote: “This [information that future 9/11 hijackers Nawaf al-Hazmi and Khalid al-Mihdhar might be in the U.S.] alarmed us sufficiently that on August 23 [2001] an immediate message went out alerting the State Department, FBI, INS [Immigration and Naturalization Services], Customs and others about the pair. …Even though they were watchlisted, that act alone did not ensure that they would be automatically placed on a no-fly list preventing them from boarding an airplane. In fact, this did not occur, and even though they were watchlisted nineteen days before 9/11, they were not found. Obviously, if we had watchlisted the two a year and a half earlier, when they first came across our radar screen, we would have had a far better chance of preventing them from subsequently entering the United States. That was essentially what happened to [9/11 facilitator] Ramzi bin al-Shibh, who, for other reasons, was several times denied entry into the United States. Al-Qa’ida simply replaced him among the plotters, and I feel the same would have happened with al-Hazmi and al-Mihdhar. CIA had multiple opportunities to notice the significant information in our holdings and watchlist al-Hazmi and al-Mihdhar. Unfortunately, until August, we missed them all.”
– George Tenet with Bill Harlow, At the Center of the Storm, Page 199