[johnthedebs]

You seem to be looking at this the wrong way. Instead, consider that once a person has decided they want to cause terror so much that they are willing to blow themselves up, they'll go to great lengths to make sure their one opportunity to do so succeeds.

These chances of passing these screenings aren't independent. They aren't just die rolls where a terrorist needs to roll 6 five times in a row for their plot to succeed. If they can improve their chances on one screening they can and will improve their chances on the rest (which was the point he was trying to make).

Now consider how much time and money is spent for each additional screening that's put into place, both for those putting it in place and the millions that have to jump through all the extra hoops each day to travel. Worth it?