Hi molponetsoka! How's it going?
I'm sure you know that you've asked a very, very, very charged question. We're all grownups here, and therefore I'm sure we all understand that the entities with the power makes the rules -- which never, somehow, seem to apply (for one reason or another) to those rule-making entities. At least that's how it is in this world.
The short answer to your question (or A short answer) is genocide: the deliberate attempt to wipe out a group of people belonging to a specific 'race,' ethnic group, religion, or what-have-you. Genocide is the ultimate crime against humanity; it is the ultimate crime against the very idea of humanity.
I am no expert in these matters, but I understand that there is sometimes some politically-motivated misapplication of the term and ambiguity of application in situations, countries where civil wars are going on. My understanding that killing in a civil war is not genocide or a crime against humanity; the killing, in this instance, is just what both or all sides 'have to do' to survive.
I always thought torture, or what the United States euphemistically calls 'enhanced interrogation techniques' was a crime against humanity, because it is a crime against the very idea of humanity -- human beings (being human beings) should not do things to other human beings like, say, make him stand on one foot all day, covered in a black hood, with fake electrodes attached to his private parts, telling him that if he lets his foot fall he will be electrocuted, for example.
Just a thought. Thanks for the question. Take it easy.