Nope, the phrase predates the CIA's use of the ter

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Etymology

https://en.wikipedia.org/wiki/Conspiracy_theory

The Oxford English Dictionary defines conspiracy theory as "the theory that an event or phenomenon occurs as a result of a conspiracy between interested parties; spec. a belief that some covert but influential agency (typically political in motivation and oppressive in intent) is responsible for an unexplained event".

It cites a 1909 article in The American Historical Review as the earliest usage example,[7][8] although it also appears in journals as early as April 1870. [9] The word "conspiracy" derives from the Latin con- ("with, together" and spirare ("to breathe" .

The historian Richard Hofstadter addressed the role of paranoia and conspiracism throughout American history in his 1964 essay "The Paranoid Style in American Politics".

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