WASHINGTON - When sudden massive violence ruptures our normal sense of safety - especially at a festive moment like Monday's Boston Marathon - the world feels grimmer and grayer for a while. There's the initial burst of fear and alarm, and then the residual pinch of tightened security, followed by the questions about which trade-offs of free movement and convenience are worth making.
Some responses go too far. Ross Douthat of The New York Times understandably argues against, at the next race or parade, "layers of extra stops and searches and checkpoints, wider and wider rings of closed streets, the kind of portable metal detectors that journalists remember unfondly from political conventions, more of the concrete barriers that Washingtonians have become accustomed to around our public buildings." Ron Fournier laments in the National Journal that "life in America changed with the Boston Marathon bombings - again, and as with past attacks, for the much worse."
He points to the Oklahoma City bombing in 1995 and the 9/11 attacks as the roots of "an obsession over domestic security and foreign wars that will mark - and mar - our generation."
True enough. But to break the mood of doom and gloom, what are the useful lessons we've learned from past bombings? How are we smarter, more prepared for emergencies, better equipped to respond and to find the perpetrators?
Let's start with the calm and, in context, sanity that has prevailed in Boston so far. My friend Juliette Kayyem, the Boston Globe columnist who served as Massachusetts Gov. Deval Patrick's homeland security adviser, credits the response at the scene to two key lessons absorbed since 9/11. "Secure site as crime scene. Move runners off quickly to avoid crowd issues," she wrote to me in an email. "This is the result of massive training for any event. We used to prep for the marathon five months in advance."
Emergency preparedness doesn't mean reducing risk to zero - it can't. As Kayyem wrote Monday, a marathon can never be totally secure for the same reason that it is so appealing: "It is a spectator event with no doors." But police and security officials have learned how to plan for worst-case scenarios in a way that makes the measurable difference we saw Monday. Here's another tangible example, from the 9/11 Commission Report: In the wake of the 1993 bombing of the World Trade Center, it took four hours to evacuate the building. On 9/11, because of the lessons learned the first time around, it took only one hour to evacuate as many as 16,000 people. And given that time was of the essence on 9/11, that was crucial lesson learned.
Boston will yield similar hard-won knowledge. If the bombs were planted in trash cans, maybe the police will seal or cart those away for the next big event. (This drives me crazy when I'm walking near the Capitol in Washington, D.C., but maybe that's just too bad.) A bigger question, posed to me by University of Toronto law professor Kent Roach, who wrote a paper on smart response strategies to past acts of terrorism, is whether we're willing to tolerate the security measures of airports at sporting events. "A marathon is tough because so many people have backpacks, but I wouldn't want to foreclose possibility of requiring people to put all their bags in one place for screening," he said. I confess that my own sense of reluctance kicks in here: Think of the time, expense and headache.
We've also learned lessons that will inform how the FBI goes about the difficult task of finding the bomber or bombers. Boston's police commissioner said Tuesday that the radius around the bombings is the most complex crime scene in the history of his department. So many people moving in and out, and so many video feeds and photos to sort through. Former White House counterterrorism coordinator Richard Clarke points out on Facebook that this is also an opportunity, albeit a laborious one.
"First, the FBI will stitch together hundreds of hours of video camera recordings from private and public surveillance and traffic cameras, as well as recordings made by private citizens attending the race," he writes. Agents will look for who left the bombs and when, and they'll use facial recognition software for identification.
"In the case of the Mossad operation in Dubai, the police in the United Arab Emirates were able to recreate most of the assassination operation by using snippets from dozens of surveillance cameras," Clarke continues. "For the FBI in Boston, a similar process has now begun."
Clarke lays out more steps the FBI and other agencies will take that are familiar to anyone who watches Homeland or any other terrorism show: Agents will look for the burner phones used to coordinate the attack and where they were purchased - maybe the buyers were caught on a store camera. They'll look for calls to suspicious numbers and monitor chat rooms used by extremist groups. They'll try to reassemble the bombs - that helped cracked the case in Oklahoma City and after the bombing of Pan Am 103 in 1988. They'll scour the flight lists in and out of Boston, including international flights, because they know that sometimes attackers try to quickly leave the country.
"In major investigations such as these, the case is usually solved either very quickly due to a lucky break or it takes months of painful detailed work," Clarke writes. "Sometimes, as in the Atlanta Olympic bombing and the TWA 800 crash, the investigation may go down a mistaken path for a time. However long it takes, these cases do get solved." If that's true, it's the silver lining of bleak repetition - we do grow wiser.
Bazelon is a Slate senior editor and writes about law, family, and kids.