quinta-feira, 28 de janeiro de 2010

Sobre o combate ao terrorismo

Bruce Schneier escreve o seguinte sobre a actual abordagem ao problema do terrorismo (ênfase meu):

«[...]To the extent security failed, it failed before Abdulmutallab even got to the airport. Why was he issued an American visa? Why didn't anyone follow up on his father's tip? While I'm sure there are things to be improved and fixed, remember that everything is obvious in hindsight. After the fact, it's easy to point to the bits of evidence and claim that someone should have "connected the dots." But before the fact, when there are millions of dots -- some important but the vast majority unimportant -- uncovering plots is a lot harder.

Despite this, the proposed fixes focus on the details of the plot rather than the broad threat. We're going to install full-body scanners, even though there are lots of ways to hide PETN -- stuff it in a body cavity, spread it thinly on a garment -- from the machines. We're going to profile people traveling from 14 countries, even though it's easy for a terrorist to travel from a different country. Seating requirements for the last hour of flight were the most ridiculous example.

The problem with all these measures is that they're only effective if we guess the plot correctly. Defending against a particular tactic or target makes sense if tactics and targets are few. But there are hundreds of tactics and millions of targets, so all these measures will do is force the terrorists to make a minor modification to their plot.

It's magical thinking: If we defend against what the terrorists did last time, we'll somehow defend against what they do next time. Of course this doesn't work. We take away guns and bombs, so the terrorists use box cutters. We take away box cutters and corkscrews, and the terrorists hide explosives in their shoes. We screen shoes, they use liquids. We limit liquids, they sew PETN into their underwear. We implement full-body scanners, and they're going to do something else. This is a stupid game; we should stop playing it.

But we can't help it. As a species, we're hardwired to fear specific stories -- terrorists with PETN underwear, terrorists on subways, terrorists with crop dusters -- and we want to feel secure against those stories. So we implement security theater against the stories, while ignoring the broad threats.

What we need is security that's effective even if we can't guess the next plot: intelligence, investigation, and emergency response. Our foiling of the liquid bombers demonstrates this. They were arrested in London, before they got to the airport. It didn't matter if they were using liquids -- which they chose precisely because we weren't screening for them -- or solids or powders. It didn't matter if they were targeting airplanes or shopping malls or crowded movie theaters. They were arrested, and the plot was foiled. That's effective security.

Finally, we need to be indomitable. The real security failure on Christmas Day was in our reaction. We're reacting out of fear, wasting money on the story rather than securing ourselves against the threat. Abdulmutallab succeeded in causing terror even though his attack failed.

If we refuse to be terrorized, if we refuse to implement security theater and remember that we can never completely eliminate the risk of terrorism, then the terrorists fail even if their attacks succeed.