Do you really think if expended even 1/4 the amount of resources we invest in the middle east on controlling our boards they'd have the slightest chance of being able to pull off another attack like that?
We could be opening every shipping container unloading , inspecting every truck, doing background checks on every inbound traveler, before admitting them and probably save tons in both blood and treasure. It would be far more effective at controlling the risk and threat of terror.
I'll admit I bought into the "we have to fight them over there..." rhetoric when Bush fed us those lines too. I know better know. I think Obama is probably the worst president of this nation has had post WWII and am still glad we did not elect McCain.
We also need to "get real" about the seriousness of the problem. 9/11 was shocking but it was a one time event they have not been able to repeat. Its hard to say for sure with all the crazy government secrecy but the evidence that is out there suggests it has not been the security apparatus that has prevented a repeat but rather the extremists own inability develop the assets here will the skill sets required to execute a successful attack. Statistically you about as likely to die falling out of bed as you are from some kind of terrorism connected event.
Considering just the lives we have "invested" in this fight we could suffer at least more several 9/11s before it will have made any kind of economic sense.
Considering the dollars, I can't find many good numbers because its hard to separate the economic costs associated with the attack from the costs we incurred in our war runup/execution. I'd be they could crash lots of jets into lots of towers with all the economic knockon effects there in before it come close though to the wealth we have thrown away in the middle east.