Earlier quoted context omitted.
The theory is, because of the checks no further attempts will be made. Its one thing to die for your cause; another to be arrested for your cause and disappear forever anonymously.
I can also carry a clown hat all day long and it will keep the pink elephants away. But there are not pink elephant! Then it means my hat is working! My theory on planes hijacking is rather that if you have a bunch of arabs taking over a plane today (after 9/11, the Paris attacks, etc), the passengers will think that doing nothing will lead to certain death, and therefore it will be impossible for the terrorists to c…
Not if you just _carry_ it it won't. Everyone knows you have to wear it.