This is the first of three novels by Robert A. Frezza set in a post-apocalyptic future where the Japanese Empire effectively rules the world and the human colonies that have been established in other star systems. One of these colonies, Suid-Afrika, is mainly populated by Boers exiled from the Republic of South Africa, but also contains a large number of colonists from the former United States.
As the novel opens, there is a war between the Boers and the "cowboys", a war that has been encouraged and (to a certain extent) subsidized by the planet's nominal owner, United Steel-Standard, a Japanese zaibatsu who in addition to extracting vital rare metals from the planet also monopolizes manufacturing on the planet. The Boers are winning, as they have the benefit of numbers and military skill, and a more or less unified government. United Steel-
Standard's planetary director, realizing that he has lost control of the situation, has panicked and called for Imperial troops to restore order.
Among those Imperial troops is Lieutenant-Colonel Anton Vereshchagin, commander of the 1st Battalion/35th Imperial Rifle Regiment. The regiment is mostly made up of Finns and Russians, with a few former rebels recruited on Ashcroft, the desert world that the 1/35th is leaving at the beginning of the novel. When the 1/35th arrives at Suid-Afrika as part of Admiral Lee's task force, matters become more complicated despite the Imperials' rapid suppression of the war and establishment of order. While the fighting between the Boers and the cowboys has ended, the secret war of the Boers against the Empire has just begun, and it is the tale of that war that the novel tells.
In the hands of another author (say, Tom Clancy) this would have been a seven hundred page doorstop of a book, but Frezza manages to deftly outline four very different cultures while describing three complicated conflicts (and a romance) in less than half that length. Moreover, he creates a cast of characters fascinating in their complexity, and the sum of it all is one of the best combat SF novels you've never heard of.