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.
