I fully agree with your assessment of the reaction (or lack thereof, and its reasons) to 9/11 by the GWB administration. It is well supported by the testimony of Richard Clarke [1] and by the investigations of senator Bob Graham [2] [3] so I don't understand why your comment gets flagged.
My point was limited in scope to the 9/11 attack itself. I think terrorism on that scale can be classified as assymetric warfare.
Warfare predates nation states. Today, most of the world is parceled into nation states. But violent non-state actors never ceased to exist. And therefore we shouldn't limit our definition of warfare only to war between nation states.