We Cannot Harden the World Against Every Attacker

Except for what appears—thank God—to be only a minor injury to a Secret Service officer who was shot near a security checkpoint, no one was hurt at the White House Correspondents’ Association Dinner last night. News reports are reassembling the mosaic of the attacker’s movements; he apparently took a train and transported some weapons with him, checked into the hotel, and then made his run at the event.These are the basic contours of all that we know, and it will take time for more credible information to emerge. In the meantime, the vacuum of facts has been filled by a certain amount of hysteria and the usual conspiracy theories, as well as understandable demands to make changes so that such a thing can never happen again.The people who were at the event are understandably shaken. Other Americans need not panic, but unfortunately, here is the list of things we can do, right now, to prevent similar attacks in the future: nothing.Well, almost nothing. One solution is to stop having public events, or to hold them exclusively in ultra-secure locations, or to lock down the area around such occasions as if they were castles surrounded by a moat, with archers on all of the parapets and the local peasantry told to shelter in place until the nobles are done with their revels.To live in an open society is to live with a very small, but nonzero, amount of risk. We cannot know if the accused attacker, Cole Tomas Allen, exploited some gap in security, but that seems at this point unlikely. I attended the dinner last year, and unless you’ve been inside the labyrinthine Washington Hilton, it’s hard to grasp just how much space exists between the lobby and the ballroom where the dinner is held. As many observers have noted, the system in place seems to have worked as intended: Allen never got close to the president.More important, the journalist Garrett M. Graff writes in a column on Substack, such security arrangements are not meant to stop everything, but one thing: “You always