Chertoff Explains the 'Why' Behind Air Security

Traveling by plane in the USA, especially in the wake of the disrupted London airliner bombing plot earlier this month, looks nothing like it before the 9/11 attacks. Liquids or gels aren't allowed in carry-ons (with a few exceptions). The rules have adapted to emerging threats (remember when nail files were forbidden?). Shoe removal is required at every airport. Air marshals have become frequent fliers, and your pilot might be armed with a gun. The government also moved to centralize the defense of the nation with the creation of the Department of Homeland Security. Its secretary, Michael Chertoff, discussed air security and other issues with USA TODAY's editorial board. His comments were edited for length and clarity.

Question: The terrorism threat comes predominantly from young, Muslim male extremists. Without racial or ethnic profiling, are there ways to make airport security better match this threat?

Answer: Yes. At the extreme, 3-year-olds are not probably a threat we need to worry about, and 75-year-old grandmothers are probably not a threat. But if you look at the experience of watching suicide bombers in other parts of the world, saying those can't be women is just not factually correct. So I'm hesitant to say that we should focus only on males, or Muslims of a particular age.

Q: So what might an airport screener look for?

A: We are training our screening officers in behavioral pattern recognition, looking at ways people behave that will actually suggest they're trying to hide something. That's a positive step that does not require ethnic profiling but looks to the pattern of behavior. I think some element of that is talking to people when they come through, asking them a few basic questions: Where are you going? What are you doing? Why are you going there? These are tools that would allow us to be more precise, but without getting into racial profiling, which is a bad thing.

Q: Have you learned any more about the chemistry of the London plot that might enable you to fine-tune the ban on liquids and gels?

A: The chemistry's still being looked at. But I actually want to come at it a different way. The question becomes not only is there a more precise way to screen out liquids you're worried about, the question is whether doing so would actually be more inconvenient than having an absolute ban. There is technology that would allow you to screen -- bottle by bottle -- whether something is dangerous. The problem is that it takes a long time. If everybody carries four bottles and it takes 15 seconds, that's a minute per person. Well, if you have 300 people boarding a jet, that's 300 minutes to board. Nobody wants to do that. The trick for us is to find a system that keeps out bad stuff and is as efficient and as convenient as possible. And sometimes it turns out that a more comprehensive ban is clearer, more easy to enforce and more efficient for the traveler.

Q: Had you identified the threat of liquids before the London plot and considered how to combat it?

A: We were aware of this as an issue, and what was particularly troubling about this scheme is how hard these guys worked to come up with ways to conceal liquids. That is what made us see the need to go to this total ban. I had actually thought of a total ban, but I had a real concern about whether it was something that would work. What alarmed me about this was that it was a very, very sophisticated way to bring components in.

Q: What role, if any, did the National Security Agency (NSA) terrorist surveillance program or the banking surveillance program play in thwarting the British terror plot?

A: I can just tell you at a very general level, the ability to monitor communications, or movement of money, is in my experience the single most important tool in stopping terrorist attacks. It's a very important tool.