“Atrocity is recognized as such by victim and perpetrator alike, by all who learn about it at whatever remove. Atrocity has no excuses, no mitigating argument. Atrocity never balances or rectifies the past. Atrocity merely arms the future for more atrocity. It is self-perpetuating upon itself — a barbarous form of incest. Whoever commits atrocity also commits those future atrocities thus bred.”