Bin Laden didn't invent terrorism or do anything to change it really. The attacks get bigger because buildings get bigger and we put more people in them at a time. These people see themselves as freedom fighters, and because of that, if we kill Bin Laden somebody will replace him and Bin Laden will become a martyr. It's not like they meet in a Terrorist Lair and refer to each other as Baron Terrorist and Archduke Terrorist.