Yeah I'm not ahthiest or anything but I think that religion has caused massacres and wars since the beginning of man. And religion (along with him bein insane) led to Hitler's regime.
If it's true, which I believe it is, it is worth every bit of it for eternal salvation. But I think we should take this conversation elsewhere because this is getting off track.
Why are all the 1900 leaders border-line(or over the border) insane?
Mostly because they were free to expand their power/influence much more quickly than in the past due to technology. You could move your soldiers/supplies/vehicles/weapons in a matter of hours/days instead of weeks/months to conquer a nation or win a battle. To control that kind of extreme power leads to extreme corruption. Also, no one challenged them. They were free to do what they wanted because any other person was too afraid to contradict them.