As Michael Scheuer, who ran the C.I.A.'s bin Laden unit until 1999, has pointed out, if bin Laden believed in Christmas, the Iraq war would be his perfect present from Santa Claus. The 9/11 attacks and the subsequent war in Afghanistan severely damaged bin Laden's organization.

When news of the first plane's hitting the World Trade Center reached them, bin Laden's followers exploded with joy. But shrewder members of al-Qaeda and the Taliban leadership in Afghanistan realized that the attacks might not be the stunning victory that bin Laden, and many in the West, took them to be.

On November 28, 2016, Abdul Razak Ali Artan, an 18-year-old legal resident of the United States whose family was originally from Somalia, used a car to mow down a group of people at the Ohio State University.