My perspective is the optimistic religious rationalist one.
We are utilizing what understanding has accrued over the course of many human worlds to bring about a Global Reconciliation.
The gurgling cultural certainty is one of "Conflict Theory", with our current status as the oh-so-traditional canary in the coalmine showing the outcome of this (frankly Aryan) Theory.
It is that there is only so much to go around (from lebensraum to status) and so whichsoever side on whichsoever day has the more popular argument, or more powerful guns, can/may/shall vanquish the other and drive them unto destruction.
My own presumption is called, "Mistake Theory", in the sense that I believe that humankind in general, and individuals in particular just... make mistakes.