A common debating tactic is to point out the very high number of people killed by atheist leaders in the 20th century as compared to religious leaders. Recently this came up here. I was asked not to continue the discussion on that post so I have moved it here.
I don’t dispute that Stalin, Mao and Pol Pot killed vast numbers of people and were atheists. But I don’t see the relevance. Atheism was just one aspect of communism and none of these leaders killed vast numbers of people because those people were religious.
Surely the reason they killed so many more than earlier leaders (who were almost all religious) was they had the opportunity. In earlier times there wasn’t the technology for mass murder and populations were far smaller so there weren’t enough people easily available to kill. Is anyone seriously suggesting that earlier leaders baulked at killing millions as opposed to hundreds of thousands because their conscience suddenly got the better of them?
In Moderation 
We shouldn’t forget the “small” numbers of people killed for heresy and the like at a very local level.
Witch hunts, crimes against morality and even adultery in some cases resulted in corporal or capital punishment usually meted out by church elders.
These small sorts of things would never appear on history’s radar, yet the deaths were very real and terrifying to those individuals who had to live in those times.
I believe you’re right on with the technology aspect.
Can you imagine the Crusaders with a thermo-nuclear device?
What about all the men, women, children, animals, and plants deliberately killed or made to suffer by the christian god and his agents and followers, as depicted in the bible? The bible that kairosfocus believes is the literal and historically accurate word of god.
And what about all the killing, suffering, and destruction going on right now in the name of religion? Are we forced to be searched at airports and other venues because of threats from “evolutionary materialists”, or from religious people who want to exterminate everyone who doesn’t have exactly the same beliefs that they do?
The whole argument is ridiculous, and kairosfocus is just stirring up trouble again with his usual falsehoods and blame shifting. Listening to him one would think that religious people have never done anything wrong and that all materialists are all evil through and through.
It is really a smear tactic used against atheism.
I’m not sure that I would call it a “debating tactic.” It has been standard apologetics for a long time, and I’m sure that it is often used in sermons. That is, the use of this kind of smear is not restricted to debating.
I suppose we could take it as an admission that they have no good argument against atheism.
And what does Hitler or Stalin or anything about atheists or materialists or Darwinists have to do with so-called “scientific” ID ‘theory’? If ID ‘theory’ is not a religious/theistic agenda, then why do the ID-ists on UD constantly bitch about atheists and materialists and Darwinists?
“I suppose we could take it as an admission that they have no good argument against atheism.”
Agreed, and from what I’ve seen they have no good arguments for or against ANYthing. They just like to argue for the sake of arguing.
As you say, does anyone really doubt that, if the combatants in past religious conflicts had access to modern weapons, the casualty rates would have been much higher? Even with the weapons of the period they still managed to chalk up some impressive statistics for death and destruction. For example, the Wikipedia article about the Thirty Years War (1618-1648) has this to say about the casualties and destruction:
By comparison, in the Second World War Germany is estimated to have lost between 8% and 10.5% of her population and Russia 13.5%. Later in the century, Pol Pot reduced the Cambodian population by around 21%.
Of course, these figures pale into insignificance compared to the Great Flood in the Bible. That accounted for almost all life on Earth if the story is to be believe and would have been genocide on a scale that twentieth-century dictators could only have dreamed of.
When Simon de Montfort led the sack of Béziers sanctioned by the papal legate” Kill them all, god will know his own”, the pretext was the harbouring of a few Cathar heretics. One might wonder that a signal was being sent to future targets of the crusaders that the price of resistance would be high. The result of the Albigensian crusade was the obliteration of the Cathar religion (Cathars refused to pay tithes and objected to the veniality of Catholic priests) and subjugation of the formerly quasi-independent Languedoc to the French monarchy. The events can be seen as political power struggle.
Similarly when Stalin, Hitler and Pol Pot were organising genocides, it was simple political motivation to permanently eliminate any perceived threats to their ambitions. It is hard to spot precise targeting of religious beliefs amongst the general mayhem.
I wonder if the motivation, religious or political, will figure at the trial of Ratko Mladić, or will his actions and their results be the issue.