Tartarize has a good post up on his blog commenting on (what I thought was) a very interesting article recently published in SciMag: The Coevolution of Parochial Altruism and War.
I highly recommend reading the article, however if you are pressed for time/don't have a subscription Tartarize has a pretty good--more laymen's argot/pragmatic--translation of what the article is basically saying:
"promoting a sort of tribalism and intergroup warfare, rejection, fear, and non-cooperation between the groups, the intragroup altruism becomes much more likely to be returned to the benefit of everybody (within the group). If you can isolate your group with respect to other groups, you both need to work together in order to succeed in these conflicts and can work together due to the much greater assurance that your gesture will be reciprocated...[sic]From a state of nature, where the life of man is solitary, poor, nasty, brutish, and short to a more peaceful altruistic world--the best path is via a small warring group where everyday is the day after 9/11. Where everybody is xenophobic and altruistic. Where you love your neighbor as yourself, but take slaves "of the strangers that do sojourn among you."
The best way to build up some trust within a group larger than your family is by forming a group, go around murdering other people, enslaving them and insuring xenophobia. This, oddly, leads to altruism. You keep people out and help people in, and can succeed in tough times and help in good times, and your entire group will be the better for it."
Though this trend is sad and unfortunate, if you look at it amorally it appears, undoubtedly, to be the very mechanism in history that has slowly united us together into everlarger groups.
Which is why I'm (perhaps a little naively) optimistic about the future. I feel that as our enemies turn into frenemies, and our frenemies into friends, we have been slowly inching towards the end of war. Globalisation (with its economic incentive for peace) has forced us to reconcile our differences and we are slowly realizing that working together is undeniably the most optimum pursuit for everybody.
Which leads us to my subscription to the utopian dream of One. I would argue (somewhat confidently) that our historical directional arrow appears to be pointing this way. Whether or not, in the end, it will be a mutually respecting consensus of states who give fair and equal concern and respect to their citizens or a hegemonic ruling of one state over the rest, or worse the failure of either resulting in the extinction of our species and even planet via nuclear weapons, I have no clue, but I can only hope for the former, and end with the annoyingly true adage: "only time will tell."