Writing in the pages of Reason on the tenth anniversary of the 9/11 attacks, the science critic Ronald Bailey calculated that since September 12, 2001, “a grand total of 30 Americans” had been “killed in terrorist incidents inside the United States.” The chance of a person in the United States “being killed by a terrorist are about one in 20 million,” Bailey proposed — odds that are far lower than those pertaining to car accidents (1 in 19,000), bath-time mishaps (1 in 80,000), and building fires (1 in 99,000). Americans, Bailey proposed, are “four times more likely to be struck by lightning than killed by a terrorist.” “Terrorism,” he concluded, “is a hollow threat.” This is a popular argument among those who believe that the United States is at present expending too much time, money, and fear in the fight against those who would strike us at home.