what makes you think decentralised groups are incapable of violence against each other and others?
violence against each other:
not incapable, but the values of many examples of currently functioning (in 2011) Band-Level and even some Tribe-Level societies suggest that violence is kept to a bare minimum and reduced to almost non-existent. things like selfishness, greed, competition and assertion of ego are intensely frowned upon in such "primitive" societies, from South Africa to Indonesia to the Amazon forests.
violence against others:
It should be clear that war arises from complex social ties, and its scale exponentially expands with the size of the social groups which are in conflict. From the level of 60 people who share everything with each other who has not much trade with other such groups, to the level of conflict between nation states which binds its citizens together with ideological conditioning, the capacity for violence increases exponentially.
how is it that a country like finland, to give one example, can achieve its level of well-being in a peaceful way, with respect for human dignity, today, within a largely capitalist framework?
this sounds like Steven Pinker's ridiculous proclamation in his new book: "Wars between developed countries have vanished...". um... vanished? really? for how long? 60 years?? that's like saying "i quit smoking. 3 minutes ago."
small pockets of peace within a constantly warring world demonstrates nothing in terms of the success of such social organization in avoiding war.
it is like saying "because 1 out of 10 Cancer patients (in this one tiny little study) did not die from it, therefore Cancer is not a fatal disease, and we should figure out a way to live with it, rather than try to find a cure".
it appears that the most common perceptual distortion when it comes to this stuff is a problem with SCALE, especially when it comes to TEMPORAL DURATION. people constantly think data from a few decades, or even a few centuries, is enough to draw some kind of conclusion. and constantly equate how humans have behaved for 10,000 years with how they have behaved for 800,000 years.
surely there is a way of living freely now, with the tools we have, and with respect for each particular culture, without having to devolve into some tribal order.
your notions of evolution and devolution, progression and regression, "advanced and civilized" VS. "primitive and under developed" are out-dated remnants of Social Darwinism, as invented by the Colonial mentality to justify its violence. Such ideas worked very well together with other "sciences" such as Eugenics and Racism in shaping the world we know today. It is the conceptual structure which makes possible things like the "civilizing nature of Empire" ---- the duty of superior white men and their western civilization to teach the brown god-less animals how to properly behave.
and can we live "freely", and peacefully, without war, within the framework of global capitalism and the structural inequity, pandemic injustice, and systematic cruelty it entails?
NO.