Asutra (1974) by Jack Vance

Gastel Etzwane and his army of Brave Free Men have driven the Roguskhoi from Durdane, only to discover that Durdane is but one tiny front- a testing ground- for an implacable enemy intent on subjugating all the worlds of man. Gastel and his people are in no position to resist, but must find a way to escape a slave army, forced to fight a war that is not their own, and defeat the Asutra!

The Asutra is part 3 of 3 of Durdane.
The land of Shant on the planet Durdane is ruled by a purposely anonymous dictator called the Anome or Faceless Man. He maintains control by virtue of the torc, a ring of explosive placed around the neck of every adult in Shan't.

Cover art by Tais Teng

https://rapidgator.net/file/b77219b97aa05a7cdbfd12d789bed1e9/

https://ddownload.com/nvg696af46lh