THE DISCOVERY AND INTERCEPTION of the London air plots was a reminder that, while our intelligence capabilities have improved since September 11, 2001, our airport-security apparatus remains antiquated. Had the terrorists executed their plan, they would have had a high probability of success. Airport security cannot possibly hope to stop similar terrorist operations in the future unless it changes dramatically.

Two options lie before us. The first and more disruptive course is to take commercial carriers out of the baggage business. Passenger tickets would include travelers and the clothes on their backs--no luggage, no carry-ons. In theory, this would lower ticket prices. Passengers could then use that savings to ship their bags ahead of them. (It's not as crazy as it sounds; some people already use FedEx for their luggage.) Today, it would cost you about $120 to send a 40-pound suitcase from a home in Philadelphia to a hotel in Los Angeles by second-day air. This price would almost certainly fall if luggage shipping became big business.

The second option is more practical, although just as radical: adopting the Israeli model of airport security. The Israelis are generally regarded as having the safest air travel in the world because, instead of searching for weapons, they use profiling to search for terrorists.

It isn't as controversial as it sounds. We're talking behavioral profiling here, not racial profiling. Israeli-style profiling first came to the United States after September 11, when Boston's Logan International Airport hired Rafi Ron as a security consultant. Before joining New Age

There are differences between Israel and America. Ben Gurion, for instance, handles 6 million to 10 million passengers per year. Logan handles 25 million to 30 million. And the United States has more than 400 commercial airports. But despite the difference in scale, the principles of the Israeli program translate surprisingly well.

"Terrorists are far from being perfect. They are people, they are human beings, just like us, and they do a lot of mistakes," Ron recently told NPR. The system Ron brought to Logan identifies terrorists by focusing on their behavior. As he explained to U.S. News & World Report, "Passengers with illegitimate, violent agendas don't act normally."

Take, for example, the 9/11 hijackers. As Transportation Security Administration analyst Carl Maccario told USA Today, when you watch the tape of the three 9/11 hijackers going through the Dulles security lines, you notice that none of them makes eye contact with security personnel. "They all looked away," says Maccario, "and had their heads down."

In 2002, Ron helped Logan institute the "behavior-pattern recognition" program, or BPR. Uniformed and plainclothes security forces look for behavior that is odd or out of the ordinary. They look for profuse sweat, stiff torsos, clenched fists, quavering Adam's apples, fidgeting, avoidance of authorities, and other markers. When an individual raises suspicion, he or she is approached for what is called a "targeted conversation."