By the standards of an earlier age, terrorism remains a limited phenomenon. That could have changed if terrorists became capable of sporadically launching destruction on a vast scale of repeatedly replicating 9/11. That hasn’t happened of course and, fortunately, it does not seem to be in the cards. While it is not true that 9/11 “changed everything,” the tragedy did have a strong impact on language, on how terrorism has come to be understood and explained. First, its apparent incidence has been multiplied by effectively re-defining insurgency as terrorism. Accordingly, the category of “civil war” may be in the process of going out of existence and the same could even happen for much international war. Second, extrapolating wildly from the apparent capacities of the 9/11 hijackers, the threat presented internationally by small bands of terrorists has been greatly exaggerated, sometimes even to the point of deeming it to be existential a process that may be repeating itself with ISIS. This paper examines these issues, and it also assesses the limited importance of the terrorism phenomenon more generally.