Michael Sherlock writes a rebuttal against the popular misconception that Hitler, Stalin, and Pol Pot were atheists and had they been real Christian their atrocities wouldn’t have happened. If they were Christians, they weren’t good Christians.
Atheism is exploding into sects, branches, and social syncretes of the tautologous but facile idea that atheism just means no gods. Yet atheists want to say they are more moral than the religious or at least as moral to show social and political acceptability. Social justice types go further and say that atheism must include some definitions of morality, or that atheist groups must pay attention to other issues, often member oriented, besides the constant screaming of there is no god.
The easy thing is to pick through history, find the tyrants-conquerers, and then discern whether they were really religious or not. The difficulty of this is that those who follow a religion rarely follow all of it; they prefer to follow certain parts of their faith and reinterpret others. The easy ploy, like “it’s all faith,” is kin to claiming “that’s not my religion.” In conquest the balance of using local religions versus imposing another is difficult. A new religion is like having a common ally against others–the alien theory of social cohesion where everyone bands to gather to fight or endorse yet another party. Or conquer lightly and infiltrate over time.
We have to look over the manifold expressions of a religion to discuss the dogma, or ideology, of the religion. If there is immorality there, then it has to be excised or others can at any time refer to the ideology as support, even, or especially, when many don’t follow that particular part. The difficult part is the response to Hitch, that atheists can’t be moral because they do not make a covenant with god. That’s why religion is systemically poisonous–its premise is no matter how you behave, unless you do it for Jesus you’re immoral–natural morality can be followed with praise but you will not be saved.
Want to make a difference? Take a small part of a religion and elevate it to high status. Old followers see commonality and comfort in familiarity and radicals see the newness and progress towards what they value. All of the time insisting that these truths are absolute and revelation or divinely inspired intuition has motivated the epistemic change.
Hitler is a fine example of a conflicted religious follower. It is unlikely that he was a devout Christian, in the common sense, (does avoiding communion mean you’re not Catholic?) though he does claim such, he does work with the papacy, and he does claim to follow god in his wars to elevate true Christians to world dominance. He mimics Luther’s hatred of Jews in a long history of Christians hating Jews. They were the Christ killers, and they were a competing religion that was having too much success yet were insular, conversion not allowed.
“Besides that, I believe one thing: there is a Lord God! And this Lord God creates the peoples.”  ~Adolf Hitler
“We were convinced that the people need and require this faith. We have therefore undertaken the fight against the atheistic movement, and that not merely with a few theoretical declarations; we have stamped it out”  ~Adolf Hitler
It would be impossible to deny that John was antisemitic.
From all of the evidence available in the volumes of historical works, both Christian and non-Christian, it is clear that there is an unbroken chain of hatred, intolerance, and racism toward the Jews, which began with “John’s” Gospel (see also the Synoptic gospels) and continued all the way down into the twentieth century, ending with Hitler’s bloody campaign against the Church’s most despised enemies. 
More than a few bible scholars have made mention of the virulent anti-Semitism of John’s gospel. This anonymous and falsely named piece of work goes beyond its synoptic counterparts (Matthew, Mark and Luke) to directly accuse the Jewish people of being the “sons of Satan” (John 8:44), thereby demonizing the Jewish people and opening the door to a millennia of Jewish suffering at the hands of credulous Christian maniacs.
But we can better blame Luther for having created World War II against semitism. It goes back through all of the wars before.
“If we wish to find a scapegoat on whose shoulders we may lay the miseries which Germany has brought on the world, I am more and more convinced that the worst evil genius of that country, is not Hitler or Bismarck or Frederick the Great, but Martin Luther.” 
Hitler was the logical conclusion of a particular kind of German destiny. In a sense he was a perfect pawn. You can be sure the US didn’t join the war for Jews though. They joined because the Germans and fascists were including Americans as part, a haven, of Jewish culture.
If Christians don’t believe it could be true that a people would consider themselves world leaders or the bearer of good news to all, let them look to their own motivations to have everyone saved, or that only through Jesus can one be saved. “With god you can do anything.” Is this really helpful? Psychs say a sky daddy gives strength. Yes, including world domination. “With democracy you can do anything.” “With kindness you can do anything.” “With economic support you can do anything.” The structure becomes meaningless–all that is heard is “you” and “anything” until reflection and then it is the subjective god.
Indeed, the heavy castigation of atheists being so militant is that atheists show the totalitarian and fascist aspects of the religious. Even though atheists are hardly represented in politics even the hint that the religious aren’t the world’s most saved and blessed people is too much to bear. It’s still a huge competition for world domination by religious factions. To disarm the very premise of this causes the religious to ban together. At least some religiosity continues the competition–the only thing worse than losing is being told the competition is invalid.
A big reason atheists hate to claim an inherent morality is many do not want an absolutist morality other than vague abstractions like reason, evidence, and science. One of the reasons many older atheists are *difficult* is that they rebelled against authority and religion long before it was popular and they never cared for any particular moral climate that was impressed upon them. They don’t want to create yet another authoritarian morality. Let atheists be democrats or republicans they say. Yet, politics is the point and always has been. Knowledge without according action is empty. Atheism must show some sort of way to action or it is utterly meaningless like “how many angels on a pin.” Reason has to show itself to morality or why use it?
Sherlock provides a good summary that so called atheists dictators were religious either self avowedly or for reasons of conquest. An ideology of conversion, good news, and idiosyncratic salvation, helps subdue people.
Jim Newman, www.frontiersofreason.com