" The cruelty could not register for her. Bloodlust, she understood. Bloodlust, she was guilty of. She had lost herself in battle, too; she had gone further than she should have, she had hurt others when she should have stopped. But this—viciousness on this scale, wanton slaughter of this magnitude, against innocents who hadn’t even lifted a finger in self-defense, this she could not imagine doing. They surrendered, she wanted to scream at her disappeared enemy. They dropped their weapons. They posed no threat to you. Why did you have to do this? A rational explanation eluded her. Because the answer could not be rational. It was not founded in military strategy. It was not because of a shortage of food rations, or because of the risk of insurgency or backlash. It was, simply, what happened when one race decided that the other was insignificant. The Federation had massacred Golyn Niis for the simple reason that they did not think of the Nikara as human. And if your opponent was not human, if your opponent was a cockroach, what did it matter how many of them you killed? What was the difference between crushing an ant and setting an anthill on fire? Why shouldn’t you pull wings off insects for your own enjoyment? The bug might feel pain, but what did that matter to you? If you were the victim, what could you say to make your tormentor recognize you as human? How did you get your enemy to recognize you at all? And why should an oppressor care? "
― R.F. Kuang , The Poppy War (The Poppy War, #1)