Today I attended the International Holocaust Remembrance Day with HE The Israeli Ambassador and the Deputy Chief of Mission. It commemorates the day 65 years ago when Allied Forces liberated Auschwitz-Birkenau Konzentrationslaeger in Poland and the over 6 million Jews who died at the hands of the Nazis. Auschwitz was the largest KzL.
The Communists like Pol Pot and the Khmer Rouge in Cambodia killed 2 million based on class and education. Those with education and what they considered bourgeoise were killed.
It is good to commemorate and remember this day and hope against hope that such catastrophes do not recur. However, with human nature being what it is, it is likely to recur, for eg in Dafur, Sudan, just to take one of many examples.