ROBERT SIEGEL, HOST:
This week's killings of Canadian soldiers - one run over by a car on Monday, one shot to death yesterday - brought to mind allegations of planned terror attacks in two other countries. Last month, Australian police charged a man they linked to ISIS with conspiring to commit demonstration killings in Australia. News reports there claim the conspirators spoke of abducting members of the public and beheading them on camera. Earlier this month in Britain, four men were arrested because authorities feared they may be planning an attack, also possibly a beheading. ISIS has urged sympathizers to commit random, public, gruesome acts of violence. So how do countries defend against that? Well, the answer, according Karen Greenberg, director of the Center on National Security at Fordham Law School in New York, is they do it differently. Karen Greenberg, welcome to the program once again.
KATIE GREENBERG: Thank you for having me.
SIEGEL: And first, tell us about the pattern here. The idea of urging people to go out and commit an attack in your native land against any nonbeliever, is that what we're seeing?
GREENBERG: Correct. I mean, this isn't a new narrative. It's just a narrative that seems to have caught on, via social media, maybe a little faster and is spreading in a little more viral way. But it's certainly not new. It was something you saw every now and then in al-Qaida statements and things like that. To your earlier question about, you know, how do you address this? You know, law enforcement has to decide whether or not to be proactive and preventive, how long they're going to follow a suspect before they arrest, you know, just where that line is. But if the person's not even on their radar and it's really that random an act, that's a whole different ball of wax.
SIEGEL: Well, in Canada this week, it seems that the two men implicated in the killings of Canadian soldiers were very much on the radar of the Canadians - so much so that their passports had been taken away. And they were supposed to be being watched. Was what Canada did about those two men very different from, let's say, the U.S. or Australia would do about them?
GREENBERG: Well, I think what U.S. law enforcement would say was, if they had a somebody who rose to the level of the counterpart of what Canada did, which was to take away their passports, this is where the FBI says that it comes in. And it engages with these individuals. It watches these individuals and may communicate with community leaders about these individuals. To say that the Canadians were watching these individuals is hard to believe given what happened. So I think that Canada had not been as proactive as the United States. In some ways, the United States has been accused of being too proactive.
SIEGEL: The Australians, when they saw information from ISIS urging these kind of killings, staged mammoth raids. Is that a different approach from what the U.S. would take or Canada took?
GREENBERG: This is something you don't - a path you probably don't want to go down as a society. You want to think twice before you react with that kind of fear. And you have to understand that to call something terrorism, you used to be talking about something organized, somebody participating in a network, rather than a self-designated individual who is psychologically unstable. And so you have to think very hard about whether you want to be mounting this massive - arrests or infiltrations the way we've seen, or if you want to begin to look at how to divert this at earlier stages and in different ways.
SIEGEL: You said that the idea of saying that the Canadians were watching the two men who were involved in this week's killings of soldiers would be - it's implausible. What should they do? Should they have been surveilling these people? Should they have confronted them face-to-face? Should they have been following them?
GREENBERG: You know, I think that it really depends on the facts, on the circumstances, which we don't know. I think confronting individuals face-to-face if you have evidence could be one thing. Reaching out to their community could be another thing. One of these young men had been turned away from his mosque a couple of years ago for his unseemly behavior that they were worried about. I think if we take away the social structures that can help law enforcement and help these individuals, we're forcing more and more alienation, which is a cause, in part, of what's happening with these young men.
SIEGEL: Thanks for talking with us today.
GREENBERG: Thanks for having me.
SIEGEL: That's Karen Greenberg who is director of the Center on National Security at Fordham Law School. Transcript provided by NPR, Copyright NPR.