Final answer:
Religious extremism, specifically the beliefs of the Islamist terrorist group al-Qaeda, was a significant cause of the 9/11 attacks. The group viewed the United States as a threat to their religious and political ideologies due to religious conflicts, political instability, and ideological beliefs.
Step-by-step explanation:
Religious extremism played a significant role in the 9/11 attacks. The extremists behind the attacks were members of the Islamist terrorist group al-Qaeda. They believed in imposing their version of Islam and viewed the United States as a threat to their religious and political ideologies.
Their actions were motivated by a combination of factors including religious conflicts, political instability, and ideological beliefs. Al-Qaeda wanted to retaliate against what they perceived as Christian invaders in Muslim holy lands. This demonstrates the significance of religious extremism as a cause of the 9/11 attacks.
To further understand the context, it is important to note that religious extremism is not exclusive to Islam. It exists in various religions and can lead to conflicts and violence if taken to an extreme level.