Economist Debates: Airport Security

By Bruce Schneier
The Economist
March 20, 2012

These essays are part of a debate with Kip Hawley, the former Administrator of the TSA. For the full debate, see The Economist's website.

German translation

Opening Remarks

Let us start with the obvious: in the entire decade or so of airport security since the attacks on America on September 11th 2001, the Transportation Security Administration (TSA) has not foiled a single terrorist plot or caught a single terrorist. Its own "Top 10 Good Catches of 2011" does not have a single terrorist on the list. The "good catches" are forbidden items carried by mostly forgetful, and entirely innocent, people -- the sorts of guns and knives that would have been just as easily caught by pre-9/11 screening procedures. Not that the TSA is expert at that; it regularly misses guns and bombs in tests and real life. Even its top "good catch" -- a passenger with C4 explosives -- was caught on his return flight; TSA agents missed it the first time through.

In previous years, the TSA has congratulated itself for confiscating home-made electronics, alerting the police to people with outstanding misdemeanour warrants and arresting people for wearing fake military uniforms. These are hardly the sorts of things we spend $8 billion annually for the TSA to keep us safe from.

Don't be fooled by claims that the plots it foils are secret. Stopping a terrorist attack is a political triumph. Witness the litany of half-baked and farcical plots that were paraded in front of the public to justify the Bush administration's anti-terrorism measures. If the TSA ever caught anything even remotely resembling a terrorist, it would be holding press conferences and petitioning Congress for a bigger budget.

The argument that the TSA, by its very existence, deters terrorist plots is equally spurious. There are two categories of terrorists. The first, and most common, is the amateurs, like the guy who crashed his plane into the Internal Revenue Service building in Austin. They are likely to be sloppy and stupid, and even pre-9/11 airplane security is going to catch them. The second is the well-briefed, well-financed and much rarer plotters. Do you really expect TSA screeners, who are busy confiscating water bottles and making people remove their belts and shoes, to stop the latter sort?

Of course not. Because the TSA's policies are based on looking backwards at previously tried tactics, it fails against professionals. Consider this century's history of aircraft terrorism. We screened for guns and bombs, so the terrorists used box cutters. We confiscated box cutters and corkscrews, so they put explosives in their sneakers. We screened footwear, so they tried to use liquids. We confiscated liquids, so they put PETN bombs in their underwear. We rolled out full-body scanners, even though they would not have caught the Underwear Bomber, so they put a bomb in a printer cartridge. We banned printer cartridges over 16 ounces -- the level of magical thinking here is amazing -- and surely in the future they will do something else.

This is a stupid game, and we should stop playing it. Overly specific security measures work only if we happen to guess both the target and the plot correctly. If we get either wrong -- if the terrorists attack something other than aircraft, or use a tactic we have not thought of yet -- we have wasted our money and uselessly annoyed millions of travellers.

Airport security is the last line of defence, and it is not a very good one. If there were only a dozen potential terrorist tactics and a hundred possible targets, then protecting against particular plots might make us safer. But there are hundreds of possible tactics and millions of possible targets. Spending billions to force the terrorists to alter their plans in one particular way does not make us safer. It is far more cost-effective to concentrate our defences in ways that work regardless of tactic and target: intelligence, investigation and emergency response.

That being said, aircraft require a special level of security for several reasons: they are a favoured terrorist target; their failure characteristics mean more deaths than a comparable bomb on a bus or train; they tend to be national symbols; and they often fly to foreign countries where terrorists can operate with more impunity.

But all that can be handled with pre-9/11 security. Exactly two things have made air travel safer since 9/11: reinforcing the cockpit door, and convincing passengers that they need to fight back. Everything else has been a waste of money. Add screening of checked bags and airport workers and we are done. All the rest is security theatre. If we truly want to be safer, we should return airport security to pre-9/11 levels and spend the savings on intelligence, investigation and emergency response.

Rebuttal Remarks

Kip Hawley's first sentence makes an impressive claim. "More than 6 billion consecutive safe arrivals of airline passengers since 9/11 mean that … airport-security measures … have been ultimately successful." Actually, they mean nothing of the sort. If anything, they mean the same thing as the more than 6 billion safe consecutive arrivals that took place before 9/11: the ones that were equally safe but happened without any annoying and obtuse security measures. They mean that terrorist plots are sufficiently rare as to make this a meaningless success metric.

Examining how effective individual security measures are at achieving their stated goals is more useful, and the results are not pretty. It is still -- in America and much of Europe at least, Britain gets this right -- trivially easy to bypass the photo ID requirement and fly while on the no-fly list. It is still trivially easy to bring as much liquid as you want through American -- again, the trick does not work in Britain -- security checkpoints. Full-body scanners do not detect the plastic explosive PETN (that's what the underwear bomber used) and you can sneak metal objects through them as well. I could go on.

Even the standard item-confiscation procedures fail. If you think about it, there are two basic kinds of contraband. If you're caught with a gun or a bomb, airport security will call the police and at the very least it will completely ruin your day. So it doesn't matter that the Transportation Security Administration (TSA) isn't 100% perfect at detecting those items; the risk of getting caught is enough that terrorists can't build a plot around them. However, if you're caught with a knife or a large bottle of liquid, the TSA agent will simply take it and let you through. This means that anything less than a 100% detection rate is ineffective, because a terrorist can repeatedly try until he succeeds.

These vulnerabilities are many years old, and this isn't the first time Mr Hawley has heard them from me. In 2007, when he was still running the TSA, I interviewed him extensively over e-mail. From my point of view, it was a fascinating back and forth of probing questions and evasive answers. (I'm sure he has a different recollection.) But the TSA continues the tradition of ducking and denying even today.

An even more meaningful response to any of these issues would be to perform a cost-benefit analysis. These sorts of analyses are standard, even with regard to rare risks, but the TSA (and, in fact, the whole Department of Homeland Security) has never conducted them on any of its programmes or technologies. It's incredible but true: he TSA does not analyse whether the security measures it deploys are worth deploying. In 2010, the National Academies of Science wrote a pretty damning report on this topic.

Filling in where the TSA and the DHS have left a void, academics have performed some cost-benefit analyses on specific airline-security measures. The results are pretty much what you would expect: the security benefits of most post-9/11 security changes do not justify the costs.

Examining the recent failed plots against planes shows that it's not post-9/11 security that prevents terrorism, but instead pre-9/11 security. Consider the 2009 underwear bomber. Because security screened for obvious bombs, Umar Abdulmutallab had to construct a unreliable bomb. Instead of using a timer or a plunger or a normal detonation mechanism, he had to resort to an ad-hoc and much more inefficient system involving a syringe, 20 minutes in the lavatory and setting his pants on fire. Not only did the bomb fail to explode, but his actions were so obvious that the other passengers noticed what was going on and subdued him. The shoe bomber, Richard Reid, was foiled in the same way.

Consider also the arrest of the liquid bombers in 2006. Again, it wasn't airport security that caught them; it was intelligence and investigation. It wouldn't have mattered if they had been using liquids or solids or gases. It wouldn't even have mattered if they had been targeting airports or shopping malls or crowded movie theatres. And it's a good thing, too; their plot was specifically designed to bypass airport security.

This latter success speaks to what I think should be done, and Mr Hawley even hints at it: "An enemy like al-Qaeda incurs trivial cost by changing attack methods to get around regulation-based security, but defensive forces have to spend disproportionately large amounts of money and effort to close off increasing numbers of new types of attack." Unfortunately he doesn't follow that line of reasoning to its logical conclusion, that our focus on planes is itself a costly waste of our security dollars. As I said in my opening remarks: "Airport security is the last line of defence, and it is not a very good one." Investing in investigation, intelligence and emergency response will keep us far safer for much less.

These financial costs are enough to demonstrate that post-9/11 security has done more harm than good, but there's much more. I'll talk about the broader social harms of these ineffective security measures in the final instalment of this debate.

Closing Statement

In my previous two statements, I made two basic arguments about post-9/11 airport security. One, we are not doing the right things: the focus on airports at the expense of the broader threat is not making us safer. And two, the things we are doing are wrong: the specific security measures put in place since 9/11 do not work. Kip Hawley doesn't argue with the specifics of my criticisms, but instead provides anecdotes and asks us to trust that airport security -- and the Transportation Security Administration (TSA) in particular -- knows what it's doing.

He wants us to trust that a 400-ml bottle of liquid is dangerous, but transferring it to four 100-ml bottles magically makes it safe. He wants us to trust that the butter knives given to first-class passengers are nevertheless too dangerous to be taken through a security checkpoint. He wants us to trust the no-fly list: 21,000 people so dangerous they're not allowed to fly, yet so innocent they can't be arrested. He wants us to trust that the deployment of expensive full-body scanners has nothing to do with the fact that the former secretary of homeland security, Michael Chertoff, lobbies for one of the companies that makes them. He wants us to trust that there's a reason to confiscate a cupcake (Las Vegas), a 3-inch plastic toy gun (London Gatwick), a purse with an embroidered gun on it (Norfolk, VA), a T-shirt with a picture of a gun on it (London Heathrow) and a plastic lightsaber that's really a flashlight with a long cone on top (Dallas/Fort Worth).

At this point, we don't trust America's TSA, Britain's Department for Transport, or airport security in general. We don't believe they're acting in the best interests of passengers. We suspect their actions are the result of politicians and government appointees making decisions based on their concerns about the security of their own careers if they don't act tough on terror, and capitulating to public demands that "something must be done".

In this final statement, I promised to discuss the broader societal harms of post-9/11 airport security. This loss of trust -- in both airport security and counterterrorism policies in general -- is the first harm. Trust is fundamental to society. There is an enormous amount written about this; high-trust societies are simply happier and more prosperous than low-trust societies. Trust is essential for both free markets and democracy. This is why open-government laws are so important; trust requires government transparency. The secret policies implemented by airport security harm society because of their very secrecy.

The humiliation, the dehumanisation and the privacy violations are also harms. That Mr Hawley dismisses these as mere "costs in convenience" demonstrates how out-of-touch the TSA is from the people it claims to be protecting. Additionally, there's actual physical harm: the radiation from full-body scanners still not publicly tested for safety; and the mental harm suffered by both abuse survivors and children: the things screeners tell them as they touch their bodies are uncomfortably similar to what child molesters say.

In 2004, the average extra waiting time due to TSA procedures was 19.5 minutes per person. That's a total economic loss -- in America -- of $10 billion per year, more than the TSA's entire budget. The increased automobile deaths due to people deciding to drive instead of fly is 500 per year. Both of these numbers are for America only, and by themselves demonstrate that post-9/11 airport security has done more harm than good.

The current TSA measures create an even greater harm: loss of liberty. Airports are effectively rights-free zones. Security officers have enormous power over you as a passenger. You have limited rights to refuse a search. Your possessions can be confiscated. You cannot make jokes, or wear clothing, that airport security does not approve of. You cannot travel anonymously. (Remember when we would mock Soviet-style "show me your papers" societies? That we've become inured to the very practice is a harm.) And if you're on a certain secret list, you cannot fly, and you enter a Kafkaesque world where you cannot face your accuser, protest your innocence, clear your name, or even get confirmation from the government that someone, somewhere, has judged you guilty. These police powers would be illegal anywhere but in an airport, and we are all harmed -- individually and collectively -- by their existence.

In his first statement, Mr Hawley related a quote predicting "blood running in the aisles" if small scissors and tools were allowed on planes. That was said by Corey Caldwell, an Association of Flight Attendants spokesman, in 2005. It was not the statement of someone who is thinking rationally about airport security; it was the voice of irrational fear.

Increased fear is the final harm, and its effects are both emotional and physical. By sowing mistrust, by stripping us of our privacy -- and in many cases our dignity -- by taking away our rights, by subjecting us to arbitrary and irrational rules, and by constantly reminding us that this is the only thing between us and death by the hands of terrorists, the TSA and its ilk are sowing fear. And by doing so, they are playing directly into the terrorists' hands.

The goal of terrorism is not to crash planes, or even to kill people; the goal of terrorism is to cause terror. Liquid bombs, PETN, planes as missiles: these are all tactics designed to cause terror by killing innocents. But terrorists can only do so much. They cannot take away our freedoms. They cannot reduce our liberties. They cannot, by themselves, cause that much terror. It's our reaction to terrorism that determines whether or not their actions are ultimately successful. That we allow governments to do these things to us -- to effectively do the terrorists' job for them -- is the greatest harm of all.

Return airport security checkpoints to pre-9/11 levels. Get rid of everything that isn't needed to protect against random amateur terrorists and won't work against professional al-Qaeda plots. Take the savings thus earned and invest them in investigation, intelligence, and emergency response: security outside the airport, security that does not require us to play guessing games about plots. Recognise that 100% safety is impossible, and also that terrorism is not an "existential threat" to our way of life. Respond to terrorism not with fear but with indomitability. Refuse to be terrorized.

earlier essay: How Changing Technology Affects Security
later essay: The Trouble with Airport Profiling
categories: Airline Travel
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Photo of Bruce Schneier by Per Ervland.

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