I think, not only Al Qaida have an ideology; they have tactics necessary to spread their ideology. And it would be a huge mistake for the United States to leave the region, to concede territory to the terrorists, to not confront them.
It seems that the most fearful people in our country are those who don't travel and are metaphorically barricaded in America. If we all stayed home and built more walls and fewer bridges between us and the rest of the world, eventually we would have something to actually be fearful of.