The One Security Improvement that has Best Prevented a 9/11 Copycat Attack

Hint: It is not federal checkpoint screening

The History Channel and WNYC Studios have launched a well-produced and sourced podcast on the events that led up to the attacks of September 11, 2001, titled Blindspot: The Road to 9/11. Hosted by WNYC’s Jim O’Grady, the podcast goes all the way back to the assassination of Rabbi Meir Kehane in 1990 by El Sayyid Nosair, who was later convicted for his role in the February 1993 bombing of the World Trade Center that killed six adults, including a pregnant woman. I highly recommend it.

The series is now four episodes deep, and I listened to the latest with great interest about the infiltrator of the terror cell that pled allegiance to Omar Abdel Rahman, the Blind Sheik, as well as the eventual arrest of the cell by the FBI’s Joint Terrorism Task Force in New York.

Episode 4 raises an interesting question about security. About a half-hour in, we learn that upon the arrest of the cell, boxes belonging to it were found filled with ideas for additional attacks against the United States.

Here’s an excerpt, with relevant portions in italics:

One box had maps of the World Trade Center. Another contained a manual on storming an airplane. It was still in fragments, but the idea for the 9/11 attacks was there in those boxes. And the FBI had it, a full eight years before it happened. In hindsight, we know what they should have done. But put yourself in that moment, when attacks like the one on 9/11 were nearly inconceivable. How much fault can you find with investigators for not making more of these fragments? A lot? A little? You don’t know?

Even in hindsight, it would be logistically impossible to shore up every conceivable target. As FBI agent John Anticev says in the podcast, there are a lot of tall buildings in New York City. But one thing was for sure: these terrorists wanted to strike the Twin Towers. Their intent in setting off the bomb in the underground garage wasn’t to merely kill a half-dozen employees, but to bring the city to its knees. It didn’t garner the success they had hoped for, so the risk that they would strike again was high.

But what to do? It wasn’t possible to harden the Twin Towers and every other skyscraper in the United States for a potential strike by what was in essence a very large missile filled with jet fuel.

In retrospect, the most important security layer implemented post-9/11 to prevent another weaponization of an aircraft wasn’t the one that was most talked about. While brand new federal checkpoint screeners and a vast expansion of the Federal Air Marshal program were improvements, it was unquestionably the hardening of cockpit doors that had the biggest impact on preventing another take-over of commercial flights.

It’s important to recognize that the key to successful large-scale terrorist attacks is the exploitation of the path of least resistance. The 9/11 hijackers knew this when they brought improvised knives and box cutters—not guns—on board their aircraft. Even if the cutting instruments had been detected (an unlikely scenario at the time) Mohammad Atta and his gang would have been allowed to board their targets with their weapons in tow. The discovery wouldn’t even have warranted a review by airport police.

Similarly, the Tsarnaev brothers exploited the fact that it was impractical, if not impossible, to prevent the carriage of backpacks into the crowd at the Boston Marathon. They blended seamlessly into the crowd of nearly identical onlookers on Boylston Street and simply left their bags on the sidewalk, a move that was obvious to no one in real time. If they had tried to leave the bags from an elevated position (say, handing from a tree or atop a mailbox), the death toll would have been astronomical, with the hundreds of catastrophic leg injuries instead occurring to the heads and torsos of innocent victims. But such an odd gesture would have brought too much attention to what they were doing.

By hardening the cockpit door and mandating that it remain closed, the federal government placed a barrier between the terrorist and the flight controls that has made “storming an airplane” not worth the attempt. To date, the existing doors have been enough of a deterrent to force terrorists to try their evil fortune in other ways. But they won’t give up.

Israeli security authorities understand this, and El Al has implemented a double-door approach for yet further security. But in the U.S., some airlines have balked at the cost, which can run up to $10,000 per door.

While that is pricey, consider this: a 2007 study by the Centre for Infrastructure Performance and Reliability found that hardened cockpit doors come at an annual cost of about $40 million. But at the same time, the Federal Air Marshal program costs about $900 million annually. And pre-board screening? That’s around $5 billion per year.

Nineteen years later, despite nearly unanimous public belief in the waning days of 2001 that American aviation would be struck again, there have been no such successful attacks. Hardened cockpit doors have been the most important layer contributing to this success, and it’s past time to improve upon them.

The threat from terrorists waging jihad remains, and it is a fact that they are playing a long game. While 19 years may seem like a long time to us, it is not to them, and it is dangerous to rest on one’s laurels in the security business. So while the TSA has dramatically improved the security of checked baggage and cargo and wisely expanded the use of K9 teams, checkpoint screening remains fraught with test failures. Dangerous weapons are still making it past screening officers, so the interiors of commercial aircraft must respond to this risk.

The Federal Aviation Administration (the agency which would mandate the installation of new and improved cockpit doors) has been accused of dragging its feet in getting recent efforts underway to force airlines to take such a measure, much to the chagrin of the the Air Line Pilots Association. Lawmakers, FAA, and TSA must remember the maxim that complacency is the enemy of excellence. They must seek constant improvements to smart, risk-based aviation security. Improving upon the quality of the current cockpit door systems would be a major step in that direction.