Malarkey. No single attack can do "incalculable loss of life and damage to property". Cause a lot of damaged nerves,yes, and pretty major economic damage, but the US is simply too big and dispersed to be significantly effected by the type attack you describe.
Cut me a break. A single nuclear attack on a major city can do incalculable damage. A biological attack can kill thousands if not more. The point of the discussion was that IF a terrorist organization or rogue state obtained these kind of weapons, it can be devastating if they use it. I did not say it would mean the end of our country. You are reading more into this than what I wrote.
We can postulate all kinds of devastating scenarios, but I am not going too. If you read the entire thread in which I responded, I was reacting to underestimating the POTENTIAL capability of a terrorist or rogue state if they obtained WMDs.