Norm, in short you are arguing that the US Government should've done more to prevent the attack.
However it is (imo) impossible to prevent the possibility of attack...it is impossible to prevent someone from taking an action.
We could've increased security at airport...made it harder for them to get in. But that would've meant that some other action would've been taken - there's always a vulnerability.
And I don't agree with your statements regarding 3rd world countries. A lot of them do hate us (imo) but not because their kids are working at 15c an hour. I think a lot of them hate us because we (as a nation) act in our self interest (rather than theirs). We'll put a dictator in power (and support them) who'll rob the people blind (and kill them) if he'll support the USA. (Saudia Arabia may be a perfect example of this.)