9/11 hasn't been a relevant threat since halfway through 9/11 Because we closed the door. Like was policy already. 9/11 could not have happened had the doors

9/11 hasn't been a relevant threat since halfway through 9/11 Because we closed the door. Like was policy already. 9/11 could not have happened had the doors been closed. The door being closed is how the Flight 93 terrorists prevented passengers from re-taking the flight.