Early 2000-Summer 2001: NSA Intercepts Communications between 9/11 Hijackers in US and Al-Qaeda Communications Hub

While the 9/11 hijackers are in the US, the NSA intercepts several calls between them and an al-Qaeda communications hub in Sana’a, Yemen, run by Ahmed al-Hada, who is hijacker Khalid Almihdhar’s father-in-law (see August 4-25, 1998).
Summary of Calls –
The first calls are made by Almihdhar and are intercepted during the spring and summer of 2000 (see Spring-Summer 2000).
More calls are made by hijacker Nawaf Alhazmi after the bombing of the USS Cole in October 2000 (see Mid-October 2000-Summer 2001).
The final call from the US is intercepted just a few weeks before 9/11 (see (August 2001)).
The NSA intercepted the hijackers’ calls outside the US before this (see Early 1999 and December 29, 1999) and continues to do so in 2000 (see Summer 2000) after Almihdhar returns to Yemen (see June 10, 2000 and (Mid-June-Mid-July 2000)).
Calls’ Content – Some of the calls may only contain non-operational information, as they are reportedly between Almihdhar and his wife. [9/11 Commission, 7/24/2004, pp. 222; Suskind, 2006, pp. 94; Wright, 2006, pp. 343] However, the calls are also used to relay messages to the 9/11 hijackers. [Embassy of Yemen (Washington), 2/13/2002; MSNBC, 2/14/2002; MSNBC, 5/2005]
Agencies’ Roles – The CIA is the lead agency monitoring the communications hub. It has planted bugs inside it and is wiretapping all calls (see Late August 1998). Intercepts of calls to and from the hub are a major plank of the US intelligence community’s effort to fight al-Qaeda. Also involved is the FBI, which is using phone records to plot these calls on a map (see Late 1998-Early 2002). Some of the calls intercepted by US intelligence come from Osama bin Laden’s satellite phone in Afghanistan (see August 4-25, 1998 and Late August 1998). After 9/11, counterterrorism officials will say that the number was one of the hottest targets being monitored by the NSA and was an “intelligence bonanza.” [Los Angeles Times, 12/21/2005; Wright, 2006, pp. 343]
Importance of Failure – Also after 9/11, counterterrorism officials will agree that the failure to follow leads to the US from this number was a huge missed opportunity to stop the 9/11 plot. For instance, FBI agent Kenneth Maxwell will say: “Two al-Qaeda guys living in California—are you kidding me? We would have been on them like white on snow: physical surveillance, electronic surveillance, a special unit devoted entirely to them.” [MSNBC, 7/21/2004; New Yorker, 7/10/2006 ]
Discussed after 9/11 – The failure to roll up the plot based on these communications intercepts will be discussed following 9/11 (see Summer 2002-Summer 2004 and March 15, 2004 and After).