It was and is important to understand that such terrorist networks, al-Qaida being only one of many, while ever adapting and changing their tactics, are incorrigible in their ideology. They are immovably fixed on the goal of killing Americans. Because they have such an extreme psychology, the civilized world cannot interact with them using the methods of negotiation and diplomacy. There are no conceivable actions which could be taken, or words which could be uttered or written, by any government, individual, or society which would cause such groups to change their primary behavior, which is murder.
The ways in which nations or cultures choose to respond to terrorism will both reflect and impact the deeper core values of those nations or cultures. For this reason, the United States should not react with a motive of revenge. Revenge not only clouds strategic and tactical thought, but it infects the soul. Vengeance is backward-looking. Instead, the primary goal must be to protect citizens from future attacks. Secretary of Defense Donald Rumsfeld writes:
A key element of the administration's policy was that the primary purpose of America's reaction to 9/11 should be the prevention of attacks and the defense of the American people, not punishment or retaliation. The only way to protect ourselves is to do after the terrorists wherever they may be. This was a more ambitious goal than the approaches previous presidents had set. It reflected Bush's view, which I shared, that 9/11 was a seminal event, not simply another typical terrorist outrage to which the world had become accustomed. The 9/11 attack showed that our enemies wanted to cause as much harm as possible to the United States - to terrorize our population and to alter the behavior of the American people. No one in the administration, as far as I know, doubted that the men who destroyed the World Trade Center and hit the Pentagon would have gladly killed ten or a hundred times the number they killed on 9/11. They were not constrained by compunction, only by the means to escalate their carnage. This meant that their potential acquisition of weapons of mass destruction - biological, chemical, or nuclear - represented a major strategic danger.
Specifically, al-Qaida had set up a workshop for the manufacture of biological and chemical weapons in the town of Khurmal. The facility, operated by an al-Qaida affiliate known as Ansar al-Islam, was documented to be producing ricin, cyanide, potassium chloride, and possibly other chemical weapons. Awareness of such operations was part of the heightened alertness in the years after 9/11. The facility in Khurmal was one more piece of data which the world was incorporating into its concept of who and what Islamic terror groups are.