FWIW they weren't arabs in a cave - the 'master mind' - Khalid Sheikh Mohammed - lived in Kuwait, has a degree in mechanical engineering and was educated in the US
The group's leader - Mohamed Atta - studied architecture at Cairo university and a University in Hamberg and was living in Germany prior to the attacks.
Don't forget the patron of the plot - Osama Bin Laden - who studied economics, business administration and civil engineering at university.
None of these guys were simply "Arabs in caves". They were modern men with modern educations living modern lives.