In any case, these dictators were not motivated in any way by their atheism. Their atheism didn't enter into the equation and as you pointed out, they represent a tiny fraction of atheists worldwide.

And it could be pointed out that there has been lots of evil done in the name of religion, such as the Albigensian Massacre which was a military and ideological campaign initiated by Pope Innocent III against the Cathars in France. And Hitler was a Xian; the German Werhmacht (Nazi military) wore belt buckles reading “Gott mit uns” meaning God is with us on their belt buckles.