When people talk about 9-11, it is important to clarify exactly "which one"? The first, in 1973, saw the removal of the Chilean government with the help of the USA, and the bringing in of a brutal dictatorship under Pinochet. In 1970, the CIA’s deputy director of plans wrote in a secret memo:
"It is firm and continuing policy that Allende be overthrown by a coup. ... It is imperative that these actions be implemented clandestinely and securely so that the USG [the U.S. government] and American hand be well hidden."