Can we advance politically beyond resentment and revenge?

Middlemen, merchants etc, often don't like warriors because they think warrior societies tend to create masters/slave relationships, but then middlemen and merchants go on to create master/slave relationships between creditors and debtors, often with feelings of resentment and revenge, as Nietzsche pointed out.

But it seems that those feelings of resentment and revenge in both warriors and merchants gradually fade the more powerful they become, then mercy and philanthropy enter their world. Power doesn't corrupt everything.

It seems to me that the same sort of mercy and philanthropy happens when we move from marauding imperialism and selfish racial supremacy to affirming ethnostates and ethnopluralism, where credence is given to the deep ethnocentric and nationalist instincts of all distinctive groups, based on the biological or genetic origin of these things in real human nature.

I believe that ethnostates and ethnopluralism are the most realistic way to obtain the most peace and social harmony for human beings with the most possible mercy and philanthropy, and with the least resentment and revenge, given that human nature remains kin-centered, gender defined, age-graded, heterosexual, marriage-making, hierarchical, ethnocentric, even xenophobic, and religious-making, among other things, with group-selection as the primary unit of successful selection, followed by individual selection.

I think of Billy Holiday singing "God bless the child that's got its own."