Nationalism is another form of tribalism, and this in turn is a consequence of the social behavior of animals (ethology), for whom group identity and territory are instinctive referents for aggressive behavior.
Once again, I dare to suggest that any human question regarding altruism must be viewed in relation to the civilizing process. Humans today continue in a process of cultural evolution aimed at achieving aggression control.
The aggressive instinct was necessary in social mammals given the struggle for scarce resources. With human intelligence and its cooperative capacity (which implies potentially infinite economic resources), the aggressive instinct now remains only an obstacle, and the entire process of civilization must be viewed in terms of the development of cultural resources to achieve the desired goal of controlling aggression. Without aggression, altruism would be the default human economic activity.
Cosmopolitanism is nothing other than non-nationalism. The default human social attitude (cooperative and caring, even with strangers we may never meet) toward all our fellow human beings.
There is no positive value in nationalism of any kind. No more than there may be, for example, in the social conception of militarism (spirit of sacrifice, camaraderie, etc.).
Pascal’s Wager is an antique. If you want to consider long-term existential risk from the perspective of obtaining possibilities for infinite bliss, you’d better turn to old Fyodorov. Fyodorov proposed eternal bliss as an altruistic action—effective altruism—by our descendants toward their ancestors (us, for example) thanks to the development of futuristic technology.
It’s especially noteworthy because Fyodorov died before Einstein postulated that time is a dimension. Today, already very accustomed to science fiction (as in the movie “Interstellar” or the TV series “Devs”), we can consider that iseveral unknown dimensions exist, all of which raises the expectation that a future altruistic humanity will rescue all of humanity from the past and grant them “infinite bliss” (physicist Frank Tipler also proposes something similar).
Furthermore, this Fyodorov thing has the advantage of being adaptable to present altruistic action. By participating in an altruistic movement, such as EA or any other past or future, we could add the incentive that we are enabling a future high-tech altruistic civilization.