Stand on Zanzibar is one of those stories that made a powerful impression on me while still at an early age. As did Shockwave Rider, one of the first cyberpunk stories, years before William Gibson's Neuromancer popularized the term in 1984.

The dystopian world you describe, of a perpetual arms race, sounds like The Jagged Orbit from 1969. I have a vague recollection of that one too, though it didn't make the sharp and deep impression of the other two.

I jumped into this thread lower down, past the tip about Wilson's book, and posted A Thought about "overpopulation of tribes" better characterizing the problem of the modern world by way of Universe 25. And it seems like tribes experiencing a lot of friction rubbing up against other tribes, might incubate muckers inside, despite their best intentions...like Muslims embedded in an increasingly hostile America. Hateful rhetoric bounces around the tribe's echo chamber, pitched to the ears of the troubled, who break out of the tribe's restraints to attack The Others, thinking that in so doing they're defending their tribe.

Tribalism's a bitch and a root cause.