I would agree with you, but then the USA did invade two countries and slaughter millions of civilians because a handful of terrorists flew a couple of planes into two NYC skyscrapers. Hell the whole existence of ISIS pretty much comes from that offensive.
America doesn't seem to get the idea that the harder they react the harder it comes back at them (9/11 itself was retaliation for stuff the US had done previously in the middle east) they constantly play the victim and the self righteous good guy even though they are just as bad in perpetuating the conflict.
Isis was in the making waaay longer than 'the war'. It was actually one of goals of Al Qaeda (ding! ding! ding!). They started the ball rolling by prodding the US into action quite successfully. My guess is they thought Afghanistan could provide them with what they wanted, but it didn't go to plan. I don't know if they banked on Bush being a total moronic jackass, but it worked and now the middle east is even more of a mess. That Bin Laden (ding! ding! ding!) was a deranged, ruthless religious nut, but a clever fellow.
They are using the same tactics again by constantly poking the bear. Will it bite? Will they do something really, really stupid. Or will we just get more wannabe mass murderers, more wide-net surveillance, more damage control, more fear, more compromises, and for what. A bunch of Jihadis whose wet dream is to nuke or gas entire cities, because religion or whatever. That's the fear behind this whole mess. Not what they are actually doing down there in the desert. Nobody gives a damn about that.
So then... Are we enabling their policies to develop and possibly materialise, while perpetuating this nonsense? Or are we just, not really afraid of these morons and their in-laws in the caves, and it's all a smoke screen? I don't think the US government cares either way. Makes for a good political platform comes election time.
In any case, the rhetoric of the last 20 years of american foreign policy is pretty clear. Freedom, democracy, good guys, bad guys, let's go get them, mission accomplished... My arse must taste like chicken.