For the moral point of this matter is never reached by calling what happened by the name of “genocide” or by counting the many millions of victims: the extermination of whole peoples had happened before in antiquity, as well as in modern colonization. It is reached only when we realize that this happened within the frame of a legal order and that the cornerstone of this “new law” consisted of the command “Thou shalt kill,” not thy enemy but innocent people who were not even potentially dangerous, and not for any reason of necessity but, on the contrary, even against all military and other utilitarian considerations.

Hannah Arendt (1906-1975) German-American philosopher, political theorist

“Personal Responsibility Under Dictatorship” (1964)
    (Source)