Bah. I think it is time we write something about ethics here. Ethical codes older than those most people now use. Because it seems a subject for confusion all too much now.
Older ethics often saw the world majorly as two groups. Family/Tribe, and other. While great consideration, care, and compassion was used within the tribe at times, there was no reason to show it to those outside most of the time.
What defined Tribe, and the layers within varied. But it was not impossible in many cases for an outsider to become tribe, even if they did not usually reach the levels of those born within. But unless they were small children, they had to earn that place. Even marriage was never a complete in, not without proof of loyalty.
Those outside your tribe might well have reason to hurt, you, and they had no reason to love you. *None*. Noe reason to keep you safe, or sane. Expecting them to was ridiculous. Almost no one took care of those outside their tribe, and even if they did, it was usually only children, and that grudgingly, until they had proven their worth. This isn't saying that people with these ethical schemes are cold, simply that you have to have earned their respect, their trust, to gain more consideration than that of basic politeness.
In fact, we all hold to variations on this kind of a system here. Some of us with more layer of modern compassion on top of it than others. Some with very little modern overlay at all. But before you label someone's behaviour as cruel, or unethical, take a moment to consider that they may simply operate from a different code.
Arcane Blades