Twenty years ago, the 9/11 attacks killed almost 3,000 Americans. Since then, the U.S. homeland hasn’t suffered any comparable terrorist assault, nor even one a tenth of the size. The total death toll from jihadist attacks inside the U.S. over these last two decades stands at 107—still too high but far lower than almost all of our leaders and counterterrorism officials feared it would be in September 2001, when visions of a follow-on strike, perhaps with weapons of mass destruction, loomed. The last jihadist attack on U.S. soil was well over a year ago, when a Saudi air force pilot with ties to al Qaeda’s branch in Yemen shot three American sailors at the Naval Air Station in Pensacola, Florida.
Yet jihadism itself remains strong, as the Taliban’s recent takeover of Afghanistan demonstrates. The U.S. has also suffered some scary near misses over the years, such as when the “underwear bomber” (who also worked with al Qaeda’s Yemen branch) almost detonated a bomb on a plane over Detroit on Christmas Day, 2009. The vast majority of plots in the U.S. have been unsophisticated, however, involving untrained volunteers inspired by ISIS or al Qaeda propaganda. The shooter behind the worst attack—Omar Mateen, who killed 49 people at a crowded Florida nightclub in 2016—pledged himself to ISIS at the last minute but had never met a member of the group.