That's a good point. The reaction to the Oklahoma City bombing and other domestic terrorism (such as the Unabomber) supports your analysis.
I think it had more to do with the scope of the attack. For example, the response to the first trade center bombing was comparable to the response to Oklahoma city.
Noah Millman wrote:
Link (which includes additional good retrospectives) thanks to Ampersand.
This article may have more political content than is suitable for LW-- if you'd rather discuss it elsewhere, I've linked it at my blog. I've posted about it here because it's an excellent example of updating and of recognizing motivated cognition even if well after the fact.