The Warren Report has never been impeached, yet conspiracy theories persist, nay thrive, after 40 years. It's fair to ask why.... Among those who believe in a conspiracy, the most widely accepted theory is that elements of the U.S. government, most conspicuously the CIA, were complicit in gunning down the 35th president in broad daylight.... How is it that Americans have come to embrace a conspiracy theory that reads like a script written by the KGB, the CIA's mortal Cold War adversary? Well, it turns out that Moscow's relentless propagation of that virulent theory and its prevalence here are no...