Believe it or not, I believe it. I’m not sure I believe that Nixon would explicitly authorize it. These were the years when the CIA was acting pretty much on its own against what the U.S. saw as the near-unstoppable onslaught of Communism, “taking the gloves off” in a way that we’ve begun to see again. I’d say it’s 50/50… the CIA put out a lot of crazy-ass plans during the Cold War that never got off the ground, and sponsored a lot of groups that went off on their own and did more crazy shit. This was done, arguably, with the best of intentions. Bottom line, though, I doubt the President (even Nixon), or anybody high-ranking in the intelligence community would knowingly unleash a plague on an innocent population.