If you could go back in time to a year before 9/11, could you prevent it from happening? How? Assume that you'd have to go back right this second, with no time to take notes or do research, and that you couldn't take anything back with you.
- Call the authorities. (Who? Why would they believe you?)
- Be a detective and expose the terrorists. (How would you find them?)
- Call in a bomb threat on 9/10 to ground the flights. (Assuming you could figure out which flights)