The wargames on morn of 9/11 from an analysis of the confused/slow response to the 4 hijacked planes and NORAD and FAA inaccuracies in testimony before 911 Commission appeared on website JusticeFor911.org :
" Military jets ordinarily available in the Northeastern Aerospace Defense Sector (NEADS) were apparently diverted to other sectors for a set of ongoing NORAD wargames (in coordination with Canada) under the headings of Northern Vigilance, Vigilant Guardian, Vigilant Warrior, Northern Guardian and possibly other, as-yet unreleased operation names (Toronto Star, 12/9/01; Aviation Week, 6/3/02; Newhouse News, 1/25/02; Richard Clarke, Against All Enemies, 2004). An additional, apparently separate drill was scheduled for 8:30 a.m. on the morning of 9/11/01, under the direction of CIA officer John Fulton. It was intended to simulate the crash of an "errant plane" into the headquarters of the National Reconnaissance Office ("NRO") near Washington (AP, 8/21/01). The government has never released a statement about whether any office was coordinating the multiple wargames and exercises held on September 11, which appear to have also involved operations within NEADS. A full investigation of the events would give priority to determining who was in charge.
NORAD personnel in Rome, New York who received first reports of hijackings within NEADS, including Col. Robert K. Marr and Lt. Col. Dawne Deskins, are reported to have asked if this was "real or exercise" (Newhouse News, 1/25/02; Aviation Week, 6/3/02). This implies that the scenarios for the wargames within NEADS on September 11 were strikingly similar to the actual attacks that unfolded that morning (as was the NRO exercise). A full investigation would explore the question of whether these wargames contributed to the confusion that prevented timely air defense response, and whether this may in fact have been intended by parties involved in the planning of the wargames in the first place, or whether information about the wargames was delivered via moles to the agents responsible for the hijackings (see, Ruppert, Crossing the Rubicon, 2004)
source: http://www.justicefor911.org/iiA1_AirDefense_111904.php
This info does lead one to wonder what are the odds that at the very time NORAD was conducting these excercises, leaving the NE quadrant of the country very vulnerable, the terrorists were in the process of hijacking and heading these planes towards NYC........how lucky could they have been?