Global Guardian is an annual training exercise sponsored by the United States Strategic Command in conjunction with Air Force Space Command and NORAD. Its main purpose is to test the military's command and control procedures in the event of nuclear warfare.
Global Guardian is performed in conjunction with "Vigilant Guardian", the annual training exercise conducted by NORAD in which a threat to North American airspace is simulated. The simulated scenario is varied from year to year.
Global Guardian and the September 11 Attacks
The September 11 attacks in 2001 occurred during that year's Global Guardian and Vigilant Guardian joint exercises. That year, according to the 9/11 Commission Report, Vigilant Guardian 'postulated a bomber attack from the former Soviet Union' on North America. The Russian 37th Air Army was, in fact, conducting major bomber exercises across the Arctic and Atlantic at this time, amongst the largest carried out by them since 1993. Both the American and the Russian exercises were cancelled after the attack.
The National Commission on Terrorist Attacks Upon the United States investigated the possibility that Vigilant Guardian preparations compromised the military's response to the attacks on September 11. They concluded that the exercise may have had, in fact, the effect of expediting the response to the attacks.
On page 17 of the 9/11 Commission Report when Boston center calls NEADS (Northeast Air Defense Sector), the response from NEADS was "is this real world or exercise?". According to the 9/11 Commission's staff statement No. 17, for instance, page 26 of the Commission's final report documents FAA's report of a "phantom flight 11" at 9:21, 35 minutes after the real flight 11 crashed into the WTC and even longer after the war games are alleged to have been aborted. However, General Ralph Eberhart told the 9/11 Commission “it took about 30 seconds” to make the adjustment to the real-world situation (note 116 to chapter 1).
The Vigilant Guardian war game was discussed in chapter 1, footnote 116 of the 9/11 Commission Report:
"On 9/11, NORAD was scheduled to conduct a military exercise, Vigilant Guardian, which postulated a bomber attack from the former Soviet Union. We investigated whether military preparations for the large-scale exercise compromised the military's response to the real-world terrorist attack on 9/11. According to General Eberhart, "it took about 30 seconds" to make the adjustment to the real-world situation. Ralph Eberhart testimony, June 17, 2004. We found that the response was, if anything, expedited by the increased number of staff at the sectors and at NORAD because of the scheduled exercise. See Robert Marr interview (Jan. 23, 2004)."