Teny Gross speaks from experience about coping in the aftermath of violence. He runs the Institute for The Study & Practice of Nonviolence in Providence.
But in the aftermath of the attack of the Boston Marathon, Gross said there is a limit to what cities can do to improve security.
"Realistically, you're going through cuts. The cities cannot even pay for regular functions. Oklahoma City happened 18 years ago. Unfortunately, there will be someone crazy who can use a fertilizer every 18 years," Gross said.
Gross said he believes that rationality will win over in the long run.
The FBI is hard at work trying to find out who plotted the attack and why. Social dialogue is also a major factor in looking for potential trigger points.
"One of the issues of the moment -- the temperatures are rising -- maybe it's the gun debate. We need to constantly be conscious of how we have those internal debates. I'm not assuming this was an internal thing, necessarily. The same would apply for foreign opponents," Gross said.
Gross said three things can be done immediately.
"One, watch the health of your discourse. How you treat others abroad and how we treat each other. B, continue with an excellent intelligence program to get to people at the source, know who potentially harms you. Try to seduce them with honey and if not, show them that there will be consequences," Gross said. "And then ... look at all your events and all sources -- we're doing it now with schools -- and do some security plans and drills."