That is why I mentioned it. Yours is IMO, a distorted perception of risk. I note that since your reading of that cited article you have tempered your over-ambitious reading of our military capability.
Aside from that, you mistake my posture of defense of homeland alone by purely defensive tactical means. I refer to defensive PURPOSE in my reference to "fortress America"; i.e., that which the Constitution allows and to which our government is morally mandated. It certainly doesn't list "provide for the common conquest" in the Preamble now matter how happy that would make Israel. The offensive tactical capability in service to that purpose starts with excellent intelligence and covert operations capabilities backed up by rapid projection of tactical military assets. It is backed up by civil defense, which has more than merely obvious constituents.
The historic problem has been that they covert actions have been covertly or even illegally funded. To allow that funding to be covert has induced many of the problems to which we now respond. An example is using the drug trade to finance such policy and the criminal industry that has grown up around it.
Both of these concepts point to a common enemy, one that USES international terrorism as a proxy for the projection of its interests and the means to weaken the rule of law under a republican government and justify extension of the infrastructure of tyranny. It is that to which I speak, as so many of its treasonous lieutenants operate within our midst. Hence my reference to its broader scope. That is not off the subject at all.
I never stated that the military operations in Afghanistan would be easy; for my purposes on this thread it was sufficient to note that they are inevitable. The difficulty of the terrain is another argument to do the military part once, and not do repeated retaliatory strikes after each attack.