El Al:
Reliance on the expertise, intelligence and judgement of individuals "on the front line" of the screening process. I would bet the manual for their job description is relatively brief, but there is extensive training, apprenticeship, and "lore." Sure, some people may be put out, and some rights may be infringed upon. If a terrorist did get through and do something horrible, I bet that the Israeli populous would have a supportive attitude toward the people who missed it, they would learn from it, and they would end up with a better system.

TSA:
Reliance on rules and mechanization. Probably view the "front line" as fully interchageable cogs (both machines and people). The manual is, I would be certain, insanely long, and it represents the "consensus of committee" in the worst way. Obviously, there is little left to common sense. When a terrorist gets through and does something horrible, the US populous/media will skewer the people who missed it. Everyone knows this, and because of it, the whole system is set up so that everyone covers their a$$e$. Nothing worthwhile will ever be learned, and an equally, if not more, ridiculous system will come out of it. Not only that, but they have to have their a$$e$ covered with regards to individual rights and affronts as well.