But terrorism has always seemed the prime known - unknown . After all , terrorism is now a depressingly regular feature of American life . While no attacks have rivaled 9/11 , we saw at least 45 thwarted terror plots in the first ten years after the destruction of the World Trade Center and in the last year alone suffered horrific losses in the San Bernardino and Orlando slaughters conflict.attack.na . But we have no template for the impact of an attack just before an American election . We are in a long war , a “ generational struggle against radical jihadist terrorism , ” as Hillary Clinton has repeatedly said .