I think a different analysis is required.
The problem with the poverty theory is that the poorest nations do not produce the most terrorists. As a nation, in fact, the present terrorist-producing regions, like Saudi Arabia, are relatively well off. (Afghanistan, a truly poor country, is not being bombed because it sent terrorists to America, but because it is a truly poor country and the United States and its allies think they need to bomb something. It's a habit, I guess.) Nor do the present terrorists claim to be fighting because of poverty; the offenses they have complained of have been religious and political offenses. I believe those who want to think about them should take them seriously; people who were willing to exercise the degree of discipline, courage and cruelty which we have recently observed were probably serious about their beliefs.