Not everyone agrees, of course, but that sort of argument has often been made by John Mueller, a political science professor at Ohio State University. Mueller asks: What's a greater threat to the United States: terrorism or our reaction to it?
For Mueller, the answer is the latter. While he concedes that we're "safer" than before, he worries that the security gains are not worth the costs. He's addressed the issue in his books Terror, Security and Money (2011) and Overblown (2006).
He told me that the search for the bombers was essential: "You can't have mass murderers running around, so spending a lot of money on policing this thing is certainly very sensible." But he worried that the incident could lead to overreactions.
"There's a tendency of managing by inbox - you know, there's an underwear bomber on a plane, so therefore we have to spend a lot more money on body scanners or things which mostly don't seem to work," he told me. Mueller is concerned that because the attack took place at a marathon, there will be a rush to increase security in ineffective ways at countless other sporting events.
Mueller argues that government should carry out its constitutional charge to "insure domestic tranquility" while spending money responsibly and wisely: "What you need to do is look at each proposal in a coherent manner to make sure that the money being spent really does reduce risk, does save lives, does help people at a cost that is sensible, and not spend on measures that don't reduce risk or . . . do it at extremely high cost, like body scanners."
He is similarly skeptical of air marshals. "They have basically done nothing since 9/11," he said. "They also cost $1.2 billion [annually]. . . . That's the entire budget of the Los Angeles police force. . . . It's been done in a very expensive manner for some reason, and it doesn't reduce the risk enough to justify its cost."
Mueller cites a Cornell study suggesting that a fear of flying after 9/11 led to increases in long-distance driving that killed more people in car accidents than died on the hijacked planes that day.
I shared Mueller's thoughts with John Timoney, who ran the police departments in Philadelphia and Miami and is now a consultant to Bahrain. He praised the Boston response and pointed out that our multiple layers of local, state, and federal law enforcement - with more than 17,000 police agencies and 700,000 to 800,000 officers - create impediments.
"On the response to terror events or some other large-scale disaster, there is always criticism for over-response or overkill," he wrote in an e-mail. "And there is some validity to this criticism. But the over-response is often due to the nature/structure of police agencies and other first responders.
"I remember the first World Trade Center bombing in 1993, when we were overwhelmed by the response of fire and ambulance services from places in New Jersey and Connecticut and Long Island. Thousands of ambulances blocked West Street [in Lower Manhattan], making it impossible to get out of the area. Six persons were killed and around 5,000 injured (mostly minor). Of the 5,000, over 4,000 made their own way to hospitals/doctors via subway or cab."
Timoney has run the Boston Marathon several times himself and lived in Cambridge when he was a fellow at Harvard. He noted that though the bombing happened in Boston, the events that followed happened in surrounding jurisdictions.
"It is a series of small communities with their own police forces and ambulances and fire departments," he wrote. "When the manhunt was under way for the bombers, it was naturally going to involve somewhat other surrounding communities. However, when the MIT police officer was killed and another seriously wounded in the chase, you just know that it was going to be a huge response. Critics might argue that someone should have been in charge to coordinate the response right away. Well, that is not going to happen."
Finally, Timoney noted the inherent difficulty of policing a marathon, but he said that a sporting event at a stadium is very different given "points of entry where people and bags can be checked."
How much we spend on such measures is a focus of Mueller's concern.
"There's no way to get risk down to zero," he told me. "An American's chance of being killed by a terrorist is about one in 3.5 million per year. . . . So the issue is, basically, if the chance of being killed by a terrorist is one in 3.5 million per year, is it worth spending a lot more money to make that even lower?"
I can think of four families that would say yes.
Michael Smerconish can be reached via www.smerconish.com.