While it sounds like a good idea on paper, the number of people who are American's that are aiding these "people" is staggering. If you start to ship them out chances are a majority of them won't be found. I hate to burst everyone bubble but if you think they accomplished these attacks without help from American's then you need to step back and think about it a little more.
Chew on this:
In order to get the maximum effect from the attacks the planes needed to hit a certain area of the building to have it implode after structural distress. How was that done? How did they get the structural plans, blueprints and floor plans needed for all the WTC buildings?
I am not going to say there are spies or traitors aiding them - however you can't think that this was all just thrown together over the period of a few months. This was years in the making and after their failure the first time, they went to great lengths to get it right the second time. And in order to do that - they needed more information.
If I were President, there wouldn't be the possibility of this happening a third time.