Anarchist's threads blow my mind more than Spaceman's. Therefore Anarchist is the new Spaceman. Sorry Spaceman. Your weirdness will not be forgotten.
Now for some solid history. I'll pick apart this little tidbit from his rant. Hunter gathers are non-violent. Partially correct but very misleading. Through early human history, hunter gathering tribes most likely rarely engaged in conflict with other tribes. This is mainly due to the fact that they rarely encountered other humans at all outside of their own community. There are still groups that live like this deep in the Amazon, for example.
You take a city the size of Chicago. The entire human population prior to agriculture was around this size, spread out around the globe. However, this didn't mean there were no internal conflicts that led to violence. You can see this by observing other great apes. Particularly our closest living relative, the chimpanzee. They often come to blows, primarily over mating. The first man to bludgeon another man with a rock was most definitely fighting over a woman. Alpha males are naturally the ones who get to breed first, and there are always beta males that will fight the alpha over that title.
Now when agriculture first arose, it was a more difficult life than hunting and gathering. Instead of just eating what you found, you now had to work to grow and nurture your food supply. Which may have actually shortened life expectancy. However, agriculture offers a more consistent food supply. Which in turn leads to surplus. With a surplus, this frees up members of the community to work on things that aren't related to food production. War evolves because now humans have finite territory which they must defend, and eventually acquire more to sustain a growing population.
Now, nomadic hunter-gatherers aren't stupid either. They see the agricultural communities have resources they can use. When your most advanced technology is a pointy stick, sacking a village to steal bows, livestock (horses especially), pottery, and food is mighty tempting. Because nomadic tribes are decentralized, it can be very difficult to fight against them. Especially when groups of tribes unify towards a single goal. In fact, one of the greatest empires the world has ever seen, was the Mongols. It largely spread militantly, defeating two of the most technologically advanced societies of the era: Islam and China.
They then used their conquered states established economies to maintain their empire.