You can also listen to William Saletan read this piece.
Every once in a while, a terrorist sets off a fatal bomb in the United States. In 1993, it was the World Trade Center. In 1995, it was Oklahoma City. In 1996, it was the Atlanta Olympics. Now it’s Boston. Each time it happens, we’re shocked.
But the attacks we see or hear about on TV are just the surface. The FBI is constantly tracking bomb plots. If you look at the bureau’s most recent cases—the ones in which it has announced investigations, arrests, indictments, convictions, or sentences since the beginning of 2012—you’ll discover that during this time frame, Boston is the 21st case involving explosives. And when you study these cases, you realize how lucky we’ve been. The next Boston may not be far behind.
Here are some of the patterns in the FBI case list:
1. Diverse targets. We expect attacks on big, iconic buildings, such as the Pentagon and the World Trade Center. Some of the recent plots fit that pattern: The perpetrators reportedly targeted or considered targeting the U.S. Capitol, the New York Stock Exchange, Grand Central Terminal, Times Square, the New York Federal Reserve Bank, a federal courthouse, and George W. Bush’s home. But others picked softer targets: electrical plants, bridges, synagogues, restaurants, bars, night clubs, malls, and a Christmas tree-lighting ceremony. Good luck protecting those places.
2. Bomb size. Three of the 20 previous cases involved car bombs. All were inoperative, thanks to prior infiltration by law enforcement. One plotter thought he was detonating a 1,000-pound bomb. Another thought he was detonating an 1,800-pound bomb. Another tested his device at a quarry and said he wanted a bigger blast. The carnage in Boston could have been worse. Much worse.
3. Everyday ingredients. Two plotters connected to al-Qaida used high explosives. But many cases involved common household items (clocks, phones, Christmas lights, auto wire, fishing weights, soda bottles) or chemicals that weren’t inherently suspicious (acetone, hydrogen peroxide, rat poison). Even the gun powder used in one explosive device was extracted from common shotgun shells. One case involved pressure cookers, a component that may have been repeated in Boston. Four cases involved pipe bombs. Three included nails. In one of these cases, nails were blasted “over a block away and at least six stories into the air.” Another nail bomb, in a reconstructed test, riddled a metal filing cabinet with holes.
4. Backpacks. If they were used to deliver the Boston bombs, that shouldn’t surprise us. Three other plotters on the 2012–13 list used them, too. One left her pack at the front doors of a courthouse. Another placed his pack along a parade route, positioned to explode into the marchers.
5. Ingenuity. Among the 20 cases, the cleverest device—too clever, apparently—was the chemical underwear bomb in Detroit, with its syringe detonator. Another perpetrator wounded a man by hiding his device in a gift basket. A third researched ways to conceal explosives in a doll or a baby carriage.
6. Luck. In three of the 20 cases, the plotters had prior contacts with al-Qaida or other known terrorist groups outside the U.S. In five other cases, the plotters reached out to fellow jihadists or jihadist wannabes, either online or through other unspecified channels. This seems to be how we infiltrated and disarmed those plots, except for the underwear bomber. We’re plugged in to the jihadist network.