What would have been an appropriate reaction to 9/11?
To strengthen security measures, to condemn it and guard against it.
But invading Afghanistan was futile and had paved the way for Islamic extremism to grow, not shrink. Bombs and guns can't defeat an ideology (unless you go down the route of complete scorched earth, eridication and genocide and remove all trace of that ideology, which to turn to those methods, makes monsters of the people carrying out), they only make it stronger. It was a reaction based on getting "justice" and making those "accountable" pay, never works, a moment of feeling you've avenged something is quickly over and the problem is worse.
The hard line Islamists are Sociopathic/Narcissistic in nature and the best way to deal with a Sociopathic/narcissistic traits is to ignore them, once you give a reaction, they then have a platform to use against you
Before 9/11 nobody even thought of Muslims hardly, 9/11 was about drawing the west into wars, which in turn makes more Muslims join their world wide cause.
I think Islam does the kind of stuff as standard and always has, I am not blaming American foreign policy for any of it (Islamists have also gained from US foreign policy too, especially in the 1980s and 1990s, funny how they forget that), however I can see its the scapegoat, "reason" and excuse they were looking for.
The way to deal with these people it too flatly say they're evil, in the same manner we treat Neo-Nazis who people flatly condemn and don't make excuses for, by stopping any excuses and conjecture that is always brought up, like "American foreign policy", "Discrimination", "well we did this to them....." etc, because it just feeds their Narcissistic persecution complex. Before 9/11 nobody even batted an eyelid about Muslims, but since 9/11 people have confronted Muslims a lot, so really Islamic extremism is the reason for so called "Islamophobia", Muslims should start being rational enough to see that themselves, that the reason they are now supposedly "marginalised" is due to the extremist element in their own religion, so then they turn to extremism themselves?
If after a bomb goes of, "westerners" get condemned for knee jerk reactions and judging all Muslims and joining groups like the EDL, Muslims who knee-jerk towards stuff against them and slip into extremism are just as ignorant, their should not be excuses made, if westerners are supposed to be rational enough to not judge all Muslims, it needs to be reinforced to Muslims to also be rational enough to not judge all westerners, to not blame the "west" as a whole for the actions of leaders and armed forces, if they cant separate differences within the west, why are we to separate differences amongst Islam? (and to be honest, I think the differences are much harder to see and the waters more "muddy" and lines blurred in Islam, sorry, this is my opinion)