Take a look at how many people die from domestic shootings in the US
It wasn't the first terrorist attack on home turf and it wasn't the last. The outrage was drummed up by the media to build support for the war. Remember the Dixie Chicks getting ostracised for speaking out against the war? They were one of the most popular artists at the time and their careers were over after that in an instant due to how gung ho everyone was. I think part of the initial support was that people were envisioning another Desert Storm, less than 50 days and done thanks to superior American training technology firepower etc. When it came to not be the case that support seemed to evaporate fast and many awoke from the collective stupor enraged at the outsized response with ill defined goals, some of the more clearly defined ones being entirely false (Saddam's WMDs).
Patriotism is a sickness that the world would be better without.
Is that what we want t tell all the revolutionaries around the world?
Would the taleban take your words to heart?
I'd replace the word patriotism with jingoism. A certain amount of pride in your country seems reasonable.