They want all JEWS DEAD along with their allies and WE WANT THE OIL. bin Laden hopes to rule the house of Saudi Arabia. Bush hopes to kill all terrorists and secure Afghanistan and Pakistan for an oil piplene. Terrorist attacks on US soil only mucks up the process further.

The economic basis can be found in this official government document.

http://commdocs.house.gov/committees/intlrel/hfa48119.000/hfa48119_0.HTM#30