How was it cowardly, Vendetta? Well, for one, it was an attack that caught the United States off its guard, unlike in a war, terrorists wait for when there is no suspicion or government "heat" on them. Secondly, it ended up killing people who did not have anything to do with them. This in itself lacks courage, at least in a war when you kill your enemy, it's a free-for-all, you're there to defend your country and the people you are hitting are in it because they know they want to be.
I dont like George W. Bush. His father was ok and I liked his administration, but I dont like his son. However, it is applaudable that he affirmed his digust for these individuals (or factions) and that he promised revenge. For all we know, these guys killed themselves in the planes and there was no one to arrest or to use as a witness. Therefore he may, like the tax refund that now may make him dip into social insurance, be blowing smoke. Yet, he is re-assuring the public, and that's what counts.
Looking at this objectively, one can understand that such an event his historically rare (worst act of terrorism ever in the united states) and it took years of planning and meeting and plotting and spying, and what have you. So, the chances of something like this happening again are in the realm of possibility, but, like Bush finding the people responsible, are thin. The best way to overcome the grief of losing a family member or friend in the damage is to put it behind and move forward. That's how I do it when something happens to someone who I know personally or have relations to.