To illustrate this point, I have an example:

I was in the Army recently (post 9/11) and I understand how our defense works, most likely better than the public (no superiority here, I was military intelligence, and worked exclusively on project 'noble eagle' which deals with domestic terrorist cells). We have hundreds of thousands of troops abroad, dealing with a threat at its "heart" when we should be more worried about its "arms".

I lived in Connecticut and went to school at Western CT St. University in Danbury. Since I had never seen the big apple, me and a couple of drunk friends decided to catch the last train there on a friday night. I boarded, and the whole way there the only person I saw was the conductor who punched my ticket. My friend's bag had metal in it, and an illegal substance, but his bag was never checked. We pulled into Grand Central Station, and went on our way.

If I had had a biological or nuclear weapon, what would have stopped me from just placing it in the station, then hopping into a car and getting the hell outta dodge? Not a damn thing, yet we spend however much money to put airborne soldiers in the 1st in Germany.

This is part of why I cashed out of the Army.