A friend who's spent a lot of time in Israel passes along this comment on why Israeli security procedures won't work in the US:
Hi, I'm an Israeli who is at least passably familiar with how the security apparatus works here. A few comments on your comments:
Scale is an issue, but nobody in the thread has touched on why. The Israeli security model is (as noted in the article) more about the passenger than their baggage. This approach is both effective, time-consuming, and "racist": the profilers have a conversation with each passenger; as I'm an Israeli Jew, I always get the abbreviated treatment -- focusing more on where my bags have been since I've packed them. As a foreigner, you get a much more in-depth grilling. As a Muslim? They want to know your shoe size, and then a whole 'nother screener comes over and asks you everything all over again, just to see that you keep your story straight. Like they say in the article, the conversations they have are not so much about what you say as how you say it. The screeners are taught to iterate a few levels deep into your story and see that it doesn't break down under scrutiny.
Naturally, this process supposes that A) the threat is foreign and mostly limited to one ethnic/religious group, and B) screeners have this sort of time.
In the US, racial profiling is... unpalatable, and if each passenger / family got even a perfunctory 1-minute Q&A session with a TSA security officer, the system would crash. The US is dealing with a larger threat profile, and a whole different order-of-magnitude of traffic.
2. The security screener's job: manpower, training, history
Normally these are intelligent men and women, usually students or twentysomethings, who pass a series of exams and then pass a several-month course. The hours are craptastic but the pay is decent, and a lot of students prefer it to shiftwork or waitressing. Passing the course is difficult but not arduous, and in the end you are really being taught guidelines on interrogation and then set loose to use your judgment -- if you have a red flag to raise, then you just call over a senior screener who has more years of experience.
The reality is that there are few enough openings that the program can be selective. I'd say, as a generalization, screeners here possess above-average intelligence, whereas your average TSA screener seems to be a working stiff, blindly following some not-too-complex screening algorithm in a three-ring binder. The number of screeners requisite for staffing all of the US airports precludes the TSA from exclusively employing screeners with the ability to make "judgment calls". There just aren't enough smart people with the desire to work a screener's job in the US.