Does anybody here watched the Michael Moore's movie Fahrenheit? There is stated clearly the 9/11 terrorist attacks were allowed (or even planned) by the big guys of the US, cause it would be the perfect excuse to start meddling with another countries (mainly the oil rich ones) under the excuse of "war on terrorism".
Even if i had not watched the movie, still it makes sense for me. I know they would do anything for oil, and the richness and power it brings... even kill innocent people of their own country.