Helping defeat Hillary Clinton is not the most successful influence operation Moscow has ever mounted against the United States. The most momentous, yes. But any covert activity that is exposed so rapidly and incites a backlash cannot be deemed an unalloyed accomplishment.

Moscow’s single most effective influence operation remains the one induced 50 years ago this month, when the now-defunct New Orleans States-Item published a front-page story on April 25, 1967, entitled “Mounting Evidence Links CIA to ‘Plot’ Probe.” It was an operation that culminated in an unimaginable achievement—inclusion in a Hollywood blockbuster by Oliver Stone that contends the CIA was instrumental in JFK's assassination.

That probe, as every conscious American knew, was district attorney Jim Garrison’s re-investigation of President Kennedy’s assassination amid a pronounced erosion of public confidence in the Warren Report. On March 1, 1967, Garrison had ostentatiously announced the arrest of Clay Shaw, a respected businessman, and charged him with complicity in JFK’s death. It was an outlandish and baseless accusation, yet Shaw would prove far from the only victim. The miscarriage of justice that unfolded over the next two years would have vast, if largely unappreciated, consequences for America’s political culture.