Questioning the official 9/11 narrative ("19 men, armed only with boxcutters..." etc) will get you fired from the Obama administration, we all recently learned. And deservedly so. To suggest that those 19 foreign nationals evaded a superpower's intelligence-gathering by any means other than their own native cunning and guile, or that anyone in the US stood to profit from the 9/11 attacks, or that the subsequent investigation avoided key areas of inquiry, is the height of folly.
The "one lone nut" theory of the Kennedy assassination was upgraded for 9/11 to "19 lone nuts plus some people in caves in Asia." Accept it or be banished from political life in the US.
Update: And if you consider it a contradiction that the US fought (and continues to fight) the most expensive military campaigns since World War II in response to the boxcutter cave guys, that is just a sign of how deeply crazy and unworthy of a job in DC you are.