This is sort of a taboo subject because fighting over territory is associated with nationalism and that, also, is a taboo subject. Peace-loving social scientists find it unrewarding to deal with subjects that might seem to justify war. Also, dealing with animal instincts in us is offensive to both the Christian Right and Marxist thinking which has to believe in the infinite maleability of human nature so they can hope to eventually drag us into egalitarial communes.
We do have all kinds of territories, however. For example, each of us has a several foot diameter invisible "box" we are alway in. Anyone who approaches us to talk to us cannot bridge that box and come closer than its border without making us uncomfortable. We instinctively then take a step back from the other person to restore that territorial border.
Another border to our territorial nature is the one surrounding our "home." We feel protective of it. Our whole private property legal system is based on it. Our home is our castle. Once, when doing insurance inspecting, I drove a little into someone's driveway as a means to then back right out and go in the opposite direction. As I hesitated in the driveway to put some things away, out came the owner in his pink pajamas in a rage yelling at me! I largely ignored him and made him so furious he picked up a big rock. It was time for me to leave! (it could only happen in California!)
There is also a territorial border to one's society and this is ideologically ignored in our secular system thinking. In an effort to bridge over the old religions with our secular system, we try to downplay the affinity we have for our own territory. Nevertheless, it explains why we are so much closer to Europe and in its interests than Asia and Africa. We are willing to treat Islam far worse than we would parts of our own society such as Australia and Latin America. We talk about the plight of Africa but give very little to help it.
It is much the same with Islam, also. It is very sensitive about Jews setting up their own government right within their society. Israel could only last because the US backs it with force and finance. Hindu society is also very territorial and has a long struggle over Kashmi behind it.
But here is the real crux of the issue: does anyone know why territorialism is the cause of human creativity and the drive behind science itself? This is an obscure subject, but not so obscure that a few brilliant scientists have not already figured it out. I've read them. It is obscure because it is largely gender-oriented! Anyone dare to deal with this . . .
charles