British intelligence agencies send a report to British Prime Minister Tony Blair and other top officials warning that al-Qaeda is in “the final stages” of preparing an attack in the West. The prediction is “based on intelligence gleaned not just from [British intelligence] but also from US agencies, including the CIA and the National Security Agency,” which cooperate with the British. “The contents of the July 16 warning would have been passed to the Americans, Whitehall sources confirmed.” The report states there is “an acute awareness” that the attack is “a very serious threat.” [London Times, 6/14/2002] This appears to be similar, but not identical, to a warning to British leaders from MI5, Britain’s domestic intelligence agency, 10 days earlier (see July 6, 2001).
August 2001: Six 9/11 Hijackers Live Near Entrance to NSA
At least six 9/11 hijackers, including all of those who boarded Flight 77, live in Laurel, Maryland, from about this time. They reportedly include Hani Hanjour, Majed Moqed, Khalid Almihdhar, Nawaf Alhazmi, and Salem Alhazmi. Laurel, Maryland, is home to a Muslim imam named Moataz Al-Hallak who teaches at a local Islamic school and has been linked to bin Laden. He has testified three times before a grand jury investigating bin Laden. NSA expert James Bamford later states, “The terrorist cell that eventually took over the airliner that crashed into the Pentagon ended up living, working, planning and developing all their activities in Laurel, Maryland, which happens to be the home of the NSA. So they were actually living alongside NSA employees as they were plotting all these things.” [Washington Post, 9/19/2001; Radio 4 ‘Today’, 6/21/2002]
August 2001: NSA Intercepts Another Call between Yemen Hub and 9/11 Hijackers Alhazmi and Almihdhar in US
The NSA has been intercepting calls between at least two 9/11 hijackers, Nawaf Alhazmi and Khalid Almihdhar, in the US and an al-Qaeda communications hub in Sana’a, Yemen, run by al-Qaeda operative Ahmed al-Hada over an approximately 18-month period before 9/11 (see Early 2000-Summer 2001). According to MSNBC, the final intercepted call comes “only weeks” before 9/11. [MSNBC, 7/21/2004] Around the same time there is great alarm in the US intelligence community over a communications intercept in Yemen indicating there was going to be a major al-Qaeda attack against US interests (see June 30-July 1, 2001). Further, the investigation of the USS Cole bombing has reignited interest in Almihdhar and Alhazmi on the part of the US intelligence community since at least June 2001 (see June 11, 2001 and July 13, 2001). The two of them are placed on an international no-fly list in late August (see August 23, 2001).
August 27-28, 2001: NSA Approves Passage of Key Information about 9/11 Hijacker Almihdhar toColeInvestigators, but FBI Headquarters Continues to Withhold It
The NSA’s representative to the FBI asks the NSA for permission to pass intelligence information about 9/11 hijackers Khalid Almihdhar and Nawaf Alhazmi to FBI criminal agents investigating the bombing of the USS Cole and permission is granted the same day, but FBI headquarters does not forward this information to the Cole investigators. The request is made on behalf of FBI headquarters agent Dina Corsi, but Corsi does not want the agents to launch a criminal investigation to find Almihdhar in the US—she believes the information will be useful to them because of Almihdhar’s connection to the Cole bombing. The information identifies Almihdhar as an “Islamic extremist” and says that he traveled to Kuala Lumpur, where he met an associate named Nawaf (see January 5-8, 2000). This links Almihdhar to the Cole bombing because the FBI thinks one of the bombers, Fahad al-Quso, may have traveled to Kuala Lumpur at the same time as Almihdhar. Although the 9/11 Commission will say that Corsi “had permission to share the information” with the Cole investigators, she apparently does not do so, even though it is clear from conversations they have around this time that they want it (see August 28, 2001, and August 28, 2001, August 28-29, 2001, and August 29, 2001). [9/11 Commission, 7/24/2004, pp. 271, 539; US Department of Justice, 11/2004, pp. 276-7, 283, 286, 294, 304 
; US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006 ]
Before September 11, 2001: FBI Squad Builds Antenna to Listen in on KSM’s Phone Calls
I-49, a squad of FBI agents and Justice Department prosecutors that began focusing on bin Laden in 1996 (see January 1996), is upset that the NSA is not sharing its monitoring of the phone calls of Khalid Shaikh Mohammed (KSM). The squad builds their own antenna in Madagascar specifically to intercept KSM’s calls. [Wright, 2006, pp. 344] It has not been revealed when this antenna was built or what was learned from this surveillance. However, there have been media reports that the NSA monitored some phone calls between KSM and Mohamed Atta in the summer of 2001 (see Summer 2001). Further, US intelligence monitored a call between KSM and Atta a day before 9/11 that was the final go-ahead for the attacks (see September 10, 2001). So presumably the I-49 squad should have known about these calls as well if this antenna did what it was designed to do.
Early September 2001: NSA Intercepts Phone Calls from Al-Qaeda Leader Zubaida to the US
The NSA intercepts “multiple phone calls from Abu Zubaida, bin Laden’s chief of operations, to the United States.” The timing and information contained in these intercepted phone calls has not been disclosed. [ABC News, 2/18/2002] In 2007, author and former CIA officer Robert Baer will comment that “apparently, when Abu Zubaida was captured, telephone records, including calls to the United States, were found in the house he was living in. The calls stopped on September 10, and resumed on September 16 (see September 16, 2001 and After). There’s nothing in the 9/11 Commission report about any of this, and I have no idea whether the leads were run down, the evidence lost or destroyed.” [Time, 12/7/2007] US intelligence had just been warned about a week earlier that Zubaida may be planning an attack on the US (see August 24, 2001). Zubaida’s exact position within al-Qaeda is disputed; he will be captured in 2002 (see March 28, 2002). It appears that a number of Western intelligence agencies were monitoring Zubaida’s calls since at least late 1998 (see October 1998 and After), and continue monitoring his calls in the weeks after 9/11 (see October 8, 2001).
September 6, 2001: NORAD Exercise Includes Terrorist Hijackers Threatening to Blow Up Airliner
The North American Aerospace Defense Command (NORAD) practices for dealing with the simulated hijackings of two commercial aircraft by terrorists, as part of its annual training exercise called Vigilant Guardian. Whether the simulated hijackings take place simultaneously or at different times of the day is unclear. [9/11 Commission, 2004; Spencer, 2008, pp. 3]
Terrorists Threaten to ‘Rain Terror from the Skies’ – One of the two exercise scenarios involves the hijacking of a Boeing 747 bound from Tokyo, Japan, to Anchorage, Alaska. According to a document later produced by the 9/11 Commission, the scenario involves the “[t]hreat of harm to [the plane’s] passengers and possibly [a] large population within [the] US or Canada.” It includes what is apparently a fictitious Asian terrorist group called “Mum Hykro,” which is threatening to “rain terror from the skies onto a major US city unless the US declares withdrawal from Asian conflict.” During the hijacking scenario, some of the plane’s passengers are killed. The plane’s course is changed to take it to Vancouver, Canada, and then to San Francisco, California. In response to the hijacking, the chairman of the Joint Chiefs of Staff and FAA headquarters direct military assistance, in the form of “covert shadowing” of the hijacked aircraft. NORAD has to liaise with the appropriate air traffic control centers. Its Alaskan region (ANR) and its Canadian region (CANR) participate in the scenario.
Group Threatens to Blow up Plane – In the other hijacking scenario, 10 members of another fictitious terrorist group, “Lin Po,” seize control of a Boeing 747 bound from Seoul, South Korea, to Anchorage. The hijackers have weapons on board that were smuggled onto the plane in small tote bags by ground crew members prior to takeoff. Gas containers were also smuggled onto the aircraft by baggage handlers before takeoff. Arming devices are attached to these containers, which can be remotely detonated. The terrorist group issues demands and threatens to blow up the plane if these are not met. The CIA and NSA caution that the group has the means and motivation to carry out a chemical and biological attack. The group kills two of the plane’s passengers and threatens to use the gas it has on board in some manner. In response to the simulated hijacking, NORAD directs fighter jets to get in a position to shoot down the hijacked airliner, and orders ANR to intercept and shadow it. In the scenario, the 747 eventually lands in Seattle, Washington. [9/11 Commission, 2004]
Most NORAD Exercises Include Hijack Scenario – Vigilant Guardian is one of four major exercises that NORAD conducts each year. Most of these exercises include a hijack scenario. [USA Today, 4/18/2004] Ken Merchant, NORAD’s joint exercise design manager, will tell the 9/11 Commission in 2003 that he cannot “remember a time in the last 33 years when NORAD has not run a hijack exercise.” [9/11 Commission, 11/14/2003 ] This year’s Vigilant Guardian will include additional aircraft hijacking scenarios on September 9 and September 10 (see September 9, 2001 and September 10, 2001), and a further simulated plane hijacking is scheduled for the morning of September 11 (see (9:40 a.m.) September 11, 2001). [9/11 Commission, 2004; Vanity Fair, 8/1/2006]
September 9, 2001: Bin Laden Tells His Stepmother that Big News Will Come in Two Days
Osama bin Laden calls his stepmother and says, “In two days, you’re going to hear big news and you’re not going to hear from me for a while.” [Daily Telegraph, 10/2/2001] US officials will later tell CNN that “in recent years they’ve been able to monitor some of bin Laden’s telephone communications with his [step]mother. Bin Laden at the time was using a satellite telephone, and the signals were intercepted and sometimes recorded.” [New York Times, 10/2/2001] Stepmother Al-Khalifa bin Laden, who raised Osama bin Laden after his natural mother died, is apparently waiting in Damascus, Syria, to meet Osama there, so he calls to cancel the meeting. [Sunday Herald (Glasgow), 10/7/2001] They had met periodically in recent years. Before 9/11, to impress important visitors, NSA analysts would occasionally play audio tapes of bin Laden talking to his stepmother. The next day government officials say about the call, “I would view those reports with skepticism.” [CNN, 10/2/2001] Bin Laden gave his natural mother a similar warning some months ago that was also overheard by the NSA (see Spring-Summer 2001).
Before September 11, 2001: US Misses Chance to Capture High-ranking Al-Qaeda Figure Due to Delay by NSA
Alec Station, the CIA’s bin Laden unit, misses a chance to capture an unnamed high-ranking al-Qaeda leader in the Netherlands. The US intelligence community learned of the chance through intercepts of al-Qaeda communications, but there is a battle over access to such intelligence. The NSA, which acquires the information, insists that it will not provide the CIA will full transcripts of calls between al-Qaeda members that it intercepts, but only with summaries of them, which the CIA finds less useful. In this case, there is a delay by the NSA in preparing the summary, and by the time it is passed to Alec Station, the al-Qaeda leader is no longer within reach. [Newsweek, 8/21/2007]
September 10, 2001: NSA Monitors Call as 9/11 Mastermind KSM Gives 9/11 Hijacker Atta Final Approval to Launch Attacks
9/11 hijacker Mohamed Atta calls 9/11 mastermind Khalid Shaikh Mohammed (KSM) in Afghanistan. KSM gives final approval to Atta to launch the attacks. The specifics of the conversation haven’t been released. [Independent, 9/15/2002] Unnamed intelligence officials later tell Knight Ridder Newspapers that the call is monitored by the NSA, but only translated after the 9/11 attacks. KSM, “using coded language, [gives] Atta final approval” for the attacks. [Knight Ridder, 9/9/2002] NSA monitored other calls between KSM and Atta in the summer of 2001 but did not share the information about this with other agencies (see Summer 2001). Additionally, it will later be revealed that an FBI squad built an antenna in the Indian Ocean some time before 9/11 with the specific purpose of listening in on KSM’s phone calls, so they may have learned about this call to Atta on their own (see Before September 11, 2001).
