- Religious extremism: bin Laden was a devout Muslim who believed that the United States was waging war against Islam. He saw the 9/11 attacks as a way to strike back at the United States and to defend the Muslim world.
- Anti-Americanism: bin Laden was also a strong opponent of American foreign policy. He believed that the United States was a corrupt and oppressive power that was exploiting the Muslim world. He saw the 9/11 attacks as a way to weaken the United States and to force it to change its policies.
- Personal grievances: bin Laden had a number of personal grievances against the United States. He was angered by the presence of American troops in Saudi Arabia, the United States' support for Israel, and the economic sanctions that were imposed on Iraq after the Gulf War. He saw the 9/11 attacks as a way to get revenge on the United States for these grievances.
- Desire for martyrdom: bin Laden believed that he was fighting a holy war against the United States and that he would be rewarded for his actions in the afterlife. He was willing to sacrifice his own life in order to carry out the attacks and to achieve his goals.
It is important to note that these are just some of the reasons why bin Laden carried out the 9/11 attacks. There are many other factors that contributed to the attacks, and it is impossible to say for sure why he made the decision to do so.