Jim Arkedis did an excellent post last week based on his work as an intelligence analyst walking you through how difficult it is is actually “connect the dots” and find a bad guy. The mathematical fact underlying the problem is, as I’ve emphasized, that since only a tiny number of people are al-Qaeda operatives, anything you do is going to be swamped with false positives. Arkedis shows this in a very granular, ground-level sense, noting that:
My goal is to find out everything we know about this individual and determine whether he’s a legitimate threat. This is no small point — in order to raise the alarm, I need definitive intelligence corroboration that the individual in question has a reported history that solidifies him as a potential danger. In other words, we don’t just arrest people because of a single report from a source of unknown quality. For the record, 99 percent of the time, walk-in sources to U.S. Embassies are of poor-to-unknown quality. That includes friends and family members who walk into the embassy and claim their relatives are potential dangers. Why? Family relations are tangled webs, and who really knows if your uncle just might want you arrested in revenge for that unsettled family land dispute.
This is one reason why it’s very important to try to promote a realistic understanding of the terrorist threat. The nature of the problem is such that we’re just not going to achieve absolute security against it. At the same time, attacks of the sort that it’s feasible for al-Qaeda to mount aren’t going to deal large objective damage to the United States. Even one person murdered by terrorists is one person too many, but there’s no feasible policy options for eliminating the risk of it. There is, however, some chance of minimizing costly misguided reactions.
It’s also true that if terrorists had entirely different capabilities, like functioning nuclear weapons, that the whole calculus would be different. But this is a policy problem of a rather limited scope. I do think, however, that some realists are wrong to minimize the risks posed by the possibility of widespread nuclear proliferation.