BlueBug,
A suicide bomber requires carrying a BOMB on the airplane. That security MIGHT be able to catch. There are actually several ways to catch them. Xray machines, Bomb sniffing devices, bomb sniffing dogs etc.
The guy that wants to fight with small bladed weapons will be much harder to stop. Security will never be able to keep knives off of airplanes. They can't keep em out of prisons where prisoners get strip searched with body cavity searches at will and have no "Rights". Yet every day in prisons around the world, prisoners are sticking shivs in each other...
Richard Reid did and didn't defeat security. Though AA corporate security picked him off, though he missed the flight the first night, the FRENCH GOVERNMENT orded AA to carry him the next day, a power they no longer have, but did at the time. At the time France was telling us we couldn't exclude anyone without cause, and though we were suspicious, we never found the bomb in his shoe. Now we can in limited circumstances refuse to carry someone. But that is part of the problem of being a "common carrier". To be fair most government had similar polices.
As to banning all hand luggage. Ummm I would love that idea myself and so would most flight attendants. But what would you do with people's purses? How about people who have to take a lot of medication? What about contact lens gear... etc. Unfortunately, though I would love to see those big rollaboard bags banned, that simply isn't going to happen in this day and age, what about those big puffy Goose Down jackets? After all they could easily be stuffed with C4. And lets not forget SHOES. Everyperson who ever complains about having to take their shoes off can thank a Richard Reid... NOT AMERICA....
Cheers
Wino