bin Laden's AL QAEDA was part of the Taliban Russian resistance in Afghanistan.
After they beat back the Russians with our help, they then focused on the US/Western presence in the ME and it's support of Israel.
The old saying, "the enemy of my enemy is my friend" surely applies.
http://www.freerepublic.com/focus/f-news/1489385/posts
My Enemy’s Enemy by George Crile