Returning vacationers will not be without a security story, and I am no exception. At the little country airport were five functionaries, two of whom, as it happened, knew me and my work but — a curious exercise of formalism — required me at flight time to fish out yet again my driver’s license, so that they could pretend to focus on the photo reassuring them that the gentleman they had been talking with was not an impostor faking a passable resemblance.

Then in came the inspector. He satisfied himself that there was nothing hidden in my shoes, but turned to my toilet case with avaricious curiosity. The line of passengers was stopped as he dug deeper and deeper into what my wife had put together for my week’s outing. Do you remember Adolphe Menjou? It was he, the tidy hair, the hairline moustache and, always, the little smile. He picked out perhaps 12 items that fell under the proscribed rubric, each containing a substance squishy (toothpaste) or liquid (shampoo). He swept the dangerous objects into a large, and presumably bombproof, canister, bound for a demolition center.

A few days later in New York, I was told by my cosmopolitan son that such vicissitudes were not to be complained about given that we are at war, and ought not even to be noticing minor and correlative impositions. One doesn’t dismiss lightly the judgments of one’s children, but an evening’s rest restored mind and body, bringing me to say: The ordeal of plane travel is properly viewed as a broken window. The idea of the broken window greatly illuminated the science of criminology when James Wilson and George Kelling reasoned that the neglect of a broken window signified the probable neglect of an adjoining skyscraper.

What we need to accept is the challenge of passenger security, because if we reduce it to looking for tubes of toothpaste, the terrorists have achieved what they desire to achieve, the activation of fear.

Suppose that in order to get from home to work you had to make your way past vicious dogs, going diagonally first left, then right. Granted, the dogs are chained and can’t get to you if you follow carefully the indicated path. But your need to do this signifies the success of the dogs as agents of terror. It’s only when the forces of peace and stability remove the menace of the dogs that you are truly shielded from concern.

The war against toothpaste intimidation can be won only by the application of intelligence. If it is intelligent to open passengers’ bags and remove the shaving cream, then it is even more intelligent to wave the passenger on when you can reasonably do so, confident that the shaving cream isn’t going to constitute a weapon of destruction. It is already, as things stand, a weapon of terror.

The only way to foil the terrorists is to contrive sensible means to gainsay their plots, real or hypothetical. The objective is to ascertain whether John Jones, carrying his medicine kit on board, is conceivably going to use something in that kit to bring down the plane. We are frozen with concern over instruments of potential destruction rather than agents of destruction. An armory of nuclear weapons that a mere finger’s touch could cause to detonate is absolutely safe if the only finger with access is that of an FBI agent trained in security.

The science of security is not inherently mysterious. We need to know something about individual passengers who board a plane. A start on this is done when you are asked to give your name. That, obviously, is only the beginning.The computer wants to know more about you, and from a properly stocked computer an official can learn — asymptotically, i.e., never attaining to absolute knowledge — what are the chances that you would want to blow up an airplane.

Ask yourself the obvious questions, and quickly you arrive at million-to-one levels of probability, which are a lot more reliable than the discovery of toothpaste in your bag. If it is unearthed that the passenger in question is a male Muslim between ages 15 and 25, then go ahead and look through his medicine kit. In failing to take into account the resources of science, we hand over to the terrorists day after day successes in thousands of airports about the world.