It’s probably fair to call our nationalism an achievement. Yes, you read me right: at least we’re now caring about more than our immediate kin and neighbors, so our tribe is vastly bigger than it was a few short millennia ago. But of course, a nation-sized tribe is not nearly big enough. Europe is beginning to increase its tribe’s size to supranational, but still smaller than global. So the next goal is the global tribe. Maybe let’s not stop there—and skip the easy steps of Solar System, Milky Way, Local Group, Virgo Supercluster, and Laniakea Supercluster. Those would all make decent tribes, given that there are additional sentient lifeforms in any of them, and we should probably strive to be part of the respective tribes.
Still, those tribes share the problems of smaller tribes: they arbitrarily separate lifeforms into groups based on chance alone, because the town a person was born in happened to be in a specific country, or the home of a lifeform happened to be in a specific supercluster.
If we want a heroic struggle, and a distinction between insider and outsider, let it be the tribe life against tribe non-life. I’m cheering for life any day. I’d like us to keep experiencing, and that should be our primary concern because everything else follows naturally. I think life is my tribe. It’s the biggest tribe I can think of. If there would be no life, the universe would be an utterly uninteresting place.