How I look at it is in a developmental model. The circle of "me" starts out very small. In fact it is incapable of seeing the other at all, except only in an object way. There is no self-identity sensed or seen in the other in an infant. As the child grows, the circle of "me" widens. Its self-identity is with the family unit. As it develops further, the circle widens again, to friends and peers. Then older still it widens to group identification. Then wider still, at a more mature stage it widens to include the community, then the nation. Still wider, still more mature, it widens to global-centric mind, including other humans as our self-identification, seeing ourselves in the stranger, the foreigner, and so forth. The yet, still wider, we see ourselves in all living things, animals, trees, and life itself. Still wider and more incluse beyond that, is all existence itself in a cosmocenrtric consciousness, the divine mind, the mind of Christ, Buddha mind.
People at the group-centric modality see others outside the group as non-humans. You see what's happening here? The less developed we are, the tighter and more narrow our world allows for the other to exist in it. It's not that problems don't exist at the higher levels. You still have boundaries. It's just that they are wider and more inclusive the more advanced or mature we are. And it's not until you realized Christ Consciousness, that there are "no boundaries".