...passes through three psychological stages to reach a comfortable acceptance of death.

• Hatred of non-Muslims or dissenting Muslims.
  
• Suppression of conscience.
  
• Acceptance of violence in the service of Allah.

Salafi religious indoctrination plays a large part, with Saudi Arabia’s Wahhabi sect being a large contributer.

It is the Salafi sect of Islam that is the cause of terrorism, not US policies inthe Middle East. Read this article by Tawfik Hamid, former member of al-Zawari's terrorist organization. Tawfik Hamid in my opinion is too harsh on moderate Muslims, but is an expert on Islamic terrorism.

There is also a Tawfik Hamid Pod-Cast interview with Point of Inquiry "My Life as a Muslim Terrorist" that is about 38 minutes (interview starts about 5 minutes in).