when expected, they wont attack (KEVIN RILEY)

I took the time to read the article by Tim Noah titled "why hasn't america been attacked since 9/11?" I think that as long as we're expecting a terrorist attack, they wont attack us. September 11 was significant because we never saw it coming. when the attack occured, i barely knew what a terrorist was. the terrorist plotted an attack big enough to make up for all of the years they weren't able to carry out a successful attack on the US. Every since we were attacked, I have been dreading another attack, and so has most of this country. It has been 7 and a half years since 9/11, and every since then there has been a "severe terrorist threat". why was the threat so low before 9/11? the terrorist are a very intelligent group of people, and as long as they know the security is beefed up everywhere around this country, they are going to take their focus elsewhere. this is the reason why places like Mumbai and london had to suffer.