correct link: http://www.salon.com/news/opinion/glenn_greenwald/

You Never Explain Why They Want To Do Us Harm! What's Their Motivation? Helen Thomas

She does pose the crucial questions, very directly.

And, of course, it is not addressed.

IMHO,  No, religion is not the motivation.  There is a sense of being wronged on their side that is not well understood.  There is also a prevalent feeling that the western society is immoral - it is tied to treatment of women in media, etc.  So, cultural issue is very much a part of the underlying rift with the west. Religion is simply the pretext.  Their religion preaches to them to cleanse the wrong wherever they see it - and it preaches that in very strong words.  And they view the west as doing things wrong.. and they are following their religion's tenets on how to go about cleansing it.  Fundamentalism gone haywire.