obviously there are no guarantees, but it is highly probable that invading iraq in '98, and thus moving into war mode, would have created entirely new security measures regarding the security of our borders, and within our borders...........this heightened security status would have made it extremely difficult, if not impossible, for the unchecked movement of the 9-11 hijackers before the event occurred
in addition, in the very same manner that the iraqi insurgency and the foreign terrorists are fighting against freedom now, had an invasion of iraq been done in '98, freedom in the middle east would be five years further along then we are now......on top of that, knowing now that all of the terrorists resources are focused in iraq, there is the likelihood that neither time nor resources would have been available for them to carry out the 9-11 attack, since they would be busy fighting in their own backyard, instead of carrying out an attack in our backyard
it could have been a real legacy for clinton, and gore would have won hands down in 2000..........but of course, hindsight is no sight, and it's not like the dems have ever had any vision anyway