Nassim Nicholas Taleb criticized the 9/11 Commission for failing to learn the real lesson of terrorism and probability.

A Black Swan is an improbable event of severe magnitude. The Commission’s recommendations will not prevent another attack as they do not address the causes of future attacks.

This is an old problem. We are blinded by hindsight bias. We assume, after the fact, that a bad even should have been prevented. We separate signals from the noise in hindsight and blame those who did not magically foretell future events.

After a military disaster, Congress likes to create “commissions” to investigate the causes. These commissions consist of career bureaucrats making the least politically controversial statements rather than actually investigating the problem. The Pearl Harbor commission and the 9/11 commission were created to symbolically scapegoat a few individuals or government agencies for the disaster. But the did nothing to prevent future surprise attacks. The Pearl Harbor commission failed to prevent the 9/11 attacks, no?

The nature of suprise attacks is surprise, afterall. In their infinite bureaucratic wisdom, commissions say surprise attacks were unsurprising.

Intelligence analysts must use Bayesian probability to incrementally update their explanations in light of new evidence. This gives them a better understanding of potential risk, but does not give them the ability to see the future.

We know that Terrorism follows a Powerlaw. It’s a self-organizing scale-free distribution of attacks and casualties. This gives us a general idea how frequent high and low casualty attacks will occur. We know a terrorist attack may kill twice as many but will only be 1/3 as probable as another terrorist attack. It’s simple statistics. This does not tell us where or how.


[The 9/11 Commission] mandate is “to provide a ‘full and complete accounting’ of the attacks of Sept. 11, 2001 and recommendations as to how to prevent such attacks in the future.”

It sounds uncontroversial, reasonable, even admirable, yet it contains at least three flaws that are common to most such inquiries into past events. To recognize those flaws, it is necessary to understand the concept of the “black swan.”

A black swan is an outlier, an event that lies beyond the realm of normal expectations. Most people expect all swans to be white because that’s what their experience tells them; a black swan is by definition a surprise. Nevertheless, people tend to concoct explanations for them after the fact, which makes them appear more predictable, and less random, than they are. Our minds are designed to retain, for efficient storage, past information that fits into a compressed narrative. This distortion, called the hindsight bias, prevents us from adequately learning from the past.

Black swans can have extreme effects: just a few explain almost everything, from the success of some ideas and religions to events in our personal lives. Moreover, their influence seems to have grown in the 20th century, while ordinary events — the ones we study and discuss and learn about in history or from the news — are becoming increasingly inconsequential.

A vicious black swan has an additional elusive property: its very unexpectedness helps create the conditions for it to occur.

The greatest flaw in the commission’s mandate, regrettably, mirrors one of the greatest flaws in modern society: it does not understand risk. The focus of the investigation should not be on how to avoid any specific black swan, for we don’t know where the next one is coming from.

I question if it is even possible to prepare for Black Swan events. Perhaps we can only seek to mitigate it’s effects, or pre-emptively attack the attacks. But those are problematic too. We cannot mitigate the damages of what we do not know will occur, nor can we attack groups before they revealed themselves.

This is already a political game. There’s the 9/11 Truther movement and other wierd political attacks on politicians and officers. Not all are as looney as the Truthers.

One seemingly reasonable criticism blames Rudy Giuliani for not updating the FDNY and NYPD radios prior to the attack. But reasonably, the radios worked under normal circumstances and would only fail in a Black Swan event. It was highly expensive to modernize radio equipment when there was seemingly no need. There seemed to be more pressing matters afterwards.

Only after the Black Swan Event, do people review every tiny, insignificant detail and find someone’s failure to see the future.

This graph helps show our limited understanding of power-law probability. For whatever reason, we are biologically driven to think in terms of normal Gaussian distributions, while we attribute powerlaw distributions to acts of God.

And so here we are. The 9/11 Commission placed the United States at greater risk by advocating additional slow-moving bureaucracies.

One military tool for evaluating risk shows the limitations of preparations is DSHARPP. It’s simple. A officer assigns every fixed and mobile point (ie: installation, ship, base etc) a 1-5 threat rating based on Demography, Susceptibility, History, Accessibility, Recognizibility, Proximity, Population. He lists the installations according to weight. 35 is a highly threatened installation, 7 is a low priority. He assigns security forces to defend likely targets. This is acceptable provided that officers constantly and incrementally update the threats. It works reasonably well against conventional militaries who think along the same lines.

Black Swan Terrorism is more problematic. It launches surprise attacks against seemingly unthreatened soft targets. They attack the unguarded points.

An officer doesn’t have enough guards to defend everything. If he sees a threat on Point B, moving Guards from point A to point B only invites an attack on point A. With terrorism, even the guards are a target. There’s no military purpose to attacks. It’s about information warfare, and causalties are made to put on TV.

Any defense requires luck to stop every attack, but the attackers only have to get lucky once. Que Sera, Sera.