Here's a good reason not to go to war:
Even most of the people who were in favor of military action said it needed to be taken by a multi-national coalition.
Not everyone praised the action in Afghanistan. Iranian Foreign Ministry spokesman Hamid Reza Asefi said the attacks "were carried out without regard to world public opinion and particularly the Islamic countries. These attacks will result in loss of life among civilians, and, therefore, they are not acceptable."
Even most of the people who were in favor of military action said it needed to be taken by a multi-national coalition.