"humans are a cooperative species"

Humans are violent, self-centered tribalists. What species are you referring to? Not homo sapiens.

Tribalism implies cooperation

This has always been and always will be an excuse for the person saying it to be a "violent, self-centered tribalist". Humans have worked together for the benefit of the community for the longest time. Rugged individualism is inherently linked to capitalism.

I think we Humans can be both cooperative species and violent,self-centered tribalists species and definitely all the grey area between the two at the same time as well.

I do mean homo sapiens. Humans are a cooperative species. They will hunt and gather together in loose communities naturally, sharing excess resources even if individuals are not directly contributing to the resource creation due to being too young, too old, sick or injured. Having inter-societal competition doesn't mean we don't still have cooperative society. Just because ants will fight other ants in different colonies doesn't mean ants are not a social species.

And every other civilized society except America builds internal power structures that inhibit violent self-centeredism. Maybe it's time we do the same?

outside of the west yes.