A few weeks ago, agents of the Transportation Security Administration assigned to Washington's Reagan National Airport stopped my mother-in-law, a very nice and unthreatening 79-year-old who was in Washington to lobby on behalf of public libraries, and asked her an enormously rude question.
She had just passed through one of the TSA's advanced imaging machines when an agent asked, rather too loudly: "Are you wearing a sanitary napkin?"
My mother-in-law has a fine sense of humor, so she wasn't terribly offended. "No. Why do you ask?" The agent responded, "Well, are you wearing anything else down there?"
At this point, my mother-in-law's traveling companion, likewise a volunteer library advocate, asked if there was a problem. "There's an anomaly in the crotch area," the agent said.
My mother-in-law was again made to raise her arms in the stick-'em-up position as the scanner looked under her clothing. Naturally, the "anomaly" disappeared. She was allowed to board her flight. Later, she asked me, "What did they think I was, a lady underpants bomber?"
There's an anomaly in the crotch area.
The answer, of course, is that they weren't thinking at all. They were responding mechanically, and crudely.
A New Bomb
This little episode was a source of laughter for those of us in her family until word came, a few days later, that Ibrahim Hassan al-Asiri, a Yemen-based bomb designer affiliated with al-Qaeda in the Arabian Peninsula, had designed a new non-metallic explosive device that could be worn like a pair of form-fitting briefs. Once detonated, it could have punched a hole through the skin of the US-bound aircraft the terrorists were targeting.
Luckily, al-Qaeda provided this underwear bomb to a double agent, who turned it over to intelligence officials. US and Saudi agents had been monitoring the plot for some time. Specialists who studied the bomb said it was more sophisticated than the one that Umar Farouk Abdulmutallab tried to detonate over Detroit in 2009.
Which raised an obvious question: Would the TSA have been able to identify this most dangerous anomaly in the crotch area, had al-Qaeda managed to build one in the US?
I asked John Pistole, the TSA's administrator, who formerly helped lead the FBI's counterterrorism efforts. He mentioned the TSA's new scanning devices, now in use at about 180 airports.
"The advanced imaging technology gives us the best chance to detect the underwear-type device," he said.
The best chance? "This is not 100 percent guaranteed," he said. "If it comes down to a terrorist who has a well-concealed device, and we have no intelligence about him, and he comes to an advanced-imaging technology machine, it is still our best technology. But it's really an open question about whether the machine, or the operator, would detect the device."
What about one of those very special TSA pat-downs? Would they help locate an underwear-shaped bomb? Pistole told me that the TSA has developed mock-ups of the bomb, and agents are being instructed on its design and how to detect it.
"If done properly, it may be found," he said.
No Perfect Security
I admire his calibrated answer. There are, in fact, many things to admire about Pistole: his willingness to take on a completely thankless job, his general forthrightness, and in particular his campaign to teach the US public, and its elected representatives, that there is no such thing as perfect security.
But I came away from our conversation unconvinced that the TSA can keep up with advances in jihadist bomb-making.
As a frequent flier who generally chooses the pat-down over the scanner (I find the scanner even more humiliating than a federally funded groping), I can say that on some occasions the manual search I experienced was so rote that I could have passed through security with a bag of grenades down my pants.
And the devil's workshop operating in Yemen under al-Asiri's direction is the obsession of counterterrorist forces worldwide precisely because it is focused on designing a bomb that will defeat airport security.
Which suggests an obvious conclusion: The existence of this latest iteration of the underwear bomb is, as the security expert Bruce Schneier argues, an advertisement against increased airport security - not in favor of it.
The chance that the government would actually ratchet back security is close to nil. But when even the head of the TSA admits that its technology might not be able to stop innovative new bombs, it might be time to look at our counterterrorism spending priorities - and focus more resources on stopping embryonic plots and less on harassing my mother-in-law.
The operation against al-Qaeda's newest bomb was a success precisely because it took place so close to the source of the plot. As Schneier points out, terrorism isn't easy. Most plots fail, and fail early.
If an underwear bomber reaches an airport, and is only a couple of hours away from boarding a plane he plans to destroy, it means that he and his co-conspirators have brought a complicated plan to maturity despite the best efforts of the most sophisticated counterterrorism campaign in history.
In other words, if the only thing standing between the bomber and his target is a TSA pat-down, bet on the bomber.
There is good news in the fight to make airport security smarter. The TSA is expanding its PreCheck expedited-screening program and will allow children under 12 and adults over 75 to keep their shoes on as they pass through scanners. Members of the military will also be treated with more flexibility.
But on what truly matters - can a TSA checkpoint prevent al-Qaeda from blowing up a civilian aircraft even if every other counterterrorism measure put in place after September 11 fails - the answer remains: probably not.