My frustration is rhetoric that subtly insults our intelligence, when it comes from people who shouldn't be subtly insulting our intelligence--i.e., allies. I just saw an ad by a gun control interest group with the tagline "We can't afford another Fort Hood."
Either you way you slice it, it would be almost impossible for that statement to be valid. Either we can afford another one, or we couldn't afford this one in the first place. "We can't afford" in general is a phrase that I generally loathe to hear in political rhetoric, unless we're talking in context of the debt or our various deficits. Nobody in their right mind actually thinks that the military would collapse or the country would disband if there were another military base shooting. This idea that America is always on the precipice of destruction and that one jerk with a gun could bring us all down is just insulting.
Now, there is an exception here...one that's fading into the past by this point. After the political fallout of September 11, and the program of civil rights abuses committed by the previous administration and largely endorsed by the public, I genuinely did fear that if there were another major terrorist attack in this country, Americans themselves would willingly (!) sacrifice their democratic power in favor of a dictatorship. Subsequent actions by the conservative movement in America from 2007 onward have verified that that portion of society already doesn't care about democracy so much as having their own people in power. That made the risk of another terror attack on Bush's watch doubly frightening. However, if similar strains of sentiment exist on the rest of the political spectrum, then the same risk exists no matter who is in power.
If the United States goes fascist, all of those "We're Rome!" people will have a lot more leg to stand on. Thankfully, I think the visceral shock and insecurity following September 11 has largely faded from the public's heart, which greatly lessens the risk that America could genuinely be destroyed by just two successful attacks.
Unthankfully, I think that a major terror attack on Obama's watch might produce an actual, bona fide rebellion. At the very least there would be riots and National Guard deployments. That would not likely threaten the stability of the nation--on the contrary, I think it would help the rest of Americans to "clean out the trash" in their minds, as it were, in finally admitting that the far right is not even remotely interested in the wellbeing of the country as a whole--but it would create a serious domestic morass in an era of fundamental economic turmoil in the capitalist system, which would suck more than we would readily imagine.