It sounds like your firsthand experience with fundamentalism was truly educational.
Many of the theorists behind Iraq War II actually espoused what you said about de-radicalizing extremists by showing them that a better, more peaceful and stable life was possible. Who knows, maybe even a few of those neocons believed it.
But it's beside the point. The problem is that the murders and genocide are happening now.
There are structures in civilization that keep violence in check. Radical fundamentalism is only one of a number of disruptive forces that can unleash the worst in humankind. Attempting to methodically address the discontent and rootlessness that drives people to extremist religions takes years or decades.
These guys are burying people alive today. Hacking off people's heads and photographing their smiling children holding up the heads today. Threatening to blow up major dams today.
I don't know if the US has much it can do effectively, or if other people elsewhere are better disposed to act. The UN is a joke. NATO has no real business in the Middle East. Opportunist nations of the region circle like vultures.
Recent history shows the US is incapable of bringing peace in the Middle East through conventional war. Recent history also shows that doing nothing except wringing hands and watching on the internet means thousands of people will die horrible deaths.
So, doing nothing doesn't work. Doing the wrong thing doesn't work. That leaves doing the right thing as the only option.
So, figuring out the right thing to do is where the debate should be. Evidence-based decision-making, not political opinion. Otherwise, the head-hackers justly believe that they are destined to prevail while cowards look the other way and have political debates instead.
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