In class we discussed competing explanations for why terrorists use violence.  Below is a link to a brief video of a press conference in which reporter Helen Thomas asks John Brennan, Deputy Assistant to the President and Deputy National Security Adviser for Homeland Security and Counterterrorism, what motivates Al Qaeda.

Watch the video, his response comes at about the 45 second mark.

Helen Thomas presses John Brennan on why Al Qaeda wants to do hard to the US

As you can see, Brennan doesn't really answer the question, and in fact avoids answering it. Why do you think he responded in that way? Does this tell us anything about his implicit theory of terrorism?