Stephen Baumgart, I think your argument against conspiracy theories is not as strong as you think. Actually, for a person who knows the history more-or-less well, it seems to be quite weak.
It is horrifyingly easy to persuade the colossal masses of people to perform nightmarishly cruel actions – not only in totalitarian states, but anywhere. Read something about the Crusades, or religious wars between the Catholic Church and various heretical movements – these were the conflicts in which a lot of “normal” people had participated, and the most shocking atrocities, often and enthusiastically done by these “normal” people, were common. Read about the European colonialism – no strict religious motivation there, yet the whole tribes were regularly sadistically massacred by the “normal” colonizers. And the totalitarian states of 20th century did not appeared out of thin air – they created by the people who were born and raised in non-totalitarian environment, yet were eager to torture and kill for the sake of their ideologies – no less eager than the denizens of “democratic” states like USA, who murdered countless victims in the “third world” countries such as Vietnam during the Cold War conflicts.
And “fear of punishment” does not work. For almost all human history, crimes and transgressions were “punished” much more severely than today. Even the mildest offences, which may lead one nowadays only to being fined, were “punished” with public beating; for the more serious crimes, one would be slowly and sadistically executed (and probably tortured for days before that, in the process of interrogation). Yet no one seemed to be frightened enough to stop committing crimes; to the contrary, the more atrocious “punishments” were used by authorities, the more violent the next rebellion was. Thieves were stealing people’s purses in the crowd which gathered to watch the cutting off hands of the thief who were caught; the gang of robbers waited for the merchant to rob near the road gallows with the mutilated corpses of their less lucky brethren. The cruelty of “punishments” did not work as deterrent, as authorities hoped. To the contrary, it worked as an example of violence as a way of life, which enraged people more and more day by day. They were not afraid; they were taught that the one the strong and victorious has the right to torture the weak and defeated any way they like. And to be strong and victorious, one should gather into gang.
The situation with institutional, powerful organization which is deliberately created to initiate violence against others, such as CIA, is even worse. If ordinary gangsters might have at least some fear of “punishment”, gangsters working for the government are almost devoid of it. After all, they are working for the very societal force which create the laws, and enforce them with initiatory violence. They are granted power above others, who are weak against the strength of the dominant system. They are no more oppressed Little Men, who live in constant fear of “punishment” for their transgressions; they are the Big Men now, ones who “punish” others, one who frighten and oppress. Whether cruel and ugly deeds they perform in their servitude for the authorities, they are most likely to be forgiven, because the rulers depend on the loyal guards who are eager to make their hands dirty to protect their superiors.
So, if one knows history, one is not persuaded by arguments like “many people cannot do terrible things”. Unfortunately, they can and do.