I'm confused. Ms. Rice states "there's no reason for the American people at this point to fear a specific threat of that kind. We have no credible evidence of a specific threat of that kind". Is it a prerequisite that our government will obtain in advance "credible evidence of a specific threat of that kind" before future terrorist action can occur? Did we have "credible evidence of a specific threat of any kind" prior to 9/11? Clearly, our enemies are performing test and evaluation of biological weapons of mass destruction on us RIGHT NOW. Our WMD deterrent is obviously in tatters. Are there some mysterious, nuclear "Marquis of Queensberry Rules" that state we must we wait until we are massively "nuked" (or gassed, or infected) ourselves before we can even CONSIDER a tactical nuclear option. Because, otherwise, rest unassured, if history is any judge, we WILL be attacked with WMD, and then we WILL use STRATEGIC, not limited tactical nuclear weapons, and it will be MASSIVE, REFLEXIVE, and without consideration for loss of innocent life. Seems perfectly reasonable to me to at least consider a tactical nuke option in order to prevent having to use inevitably massive ones later.
Are there some mysterious, nuclear "Marquis of Queensberry Rules" that state we must we wait until we are massively "nuked" (or gassed, or infected) ourselves before we can even CONSIDER a tactical nuclear option.
Nope, our nuke doctrine is clear, and according to it, we should have retaliated on 9/11, because those four jets did comprise a WMD.
But, we're too hobbled by the left, by PC, and by fear. So, we lie to our people. We tell them that an obvious bio attack is just a series of "isolated incidents". We say don't worry, buy a car. No big deal, it's nothing to sweat, just take antibiotics, blah blah blah.
Then they prove it's a lie (to the 3 or 4 people who actually believed 'em) by running like scared rabbits when their workplace gets dusted.
So, in summary -- and to address your question -- it's not that the threshhold for a response is artificially high -- it's that they are denying that it's been crossed, because they don't want to implement it.
This sort of ambivilance only accomplishes one thing: it tells the enemy that we are paper tigers. That we're weak. That we're safe to hit.