A regiment of Falkenberg’s Legion has come to Sparta to set up a standing army for them. They came just in time for Senator Bronson has been financing an insurgency. The Liberation Army of Sparta or the Helots have started to flex their muscles. They start with terrorism and low intensity guerilla war. There is also a traitor in the form of a Spartan senator named Dion Croser. He leads the political segment of the Non-Citizen Liberation Front or NCLF. A series of high-profile terrorist attacks shows the level of power they have achieved. Bronson has hired the best mercenaries in the form of technoninjas from the planet Meiji. The story culminates in a big battle between the Helots and the untried Spartan Royal Army. A battle where the Helots use poison gas to try and deliver a final blow.
Pournelle decided to get Stirling to help him with the further adventures of Falkenberg’s Legion. I can see his influence in the pseudo encyclopedia entries at the beginning of each chapter that deals with some fictional history or place the chapter deals with. I think the character of Skilly the Belizean gang leader turned Maoist guerilla is also his creation. The action now comes to the planet Sparta which is the future place where the Empire of Man is formed. We explore this fascinating society founded by American intellectuals based on the freedoms of the old America. It does have a society of freedom and the ability of upward mobility. They are a democracy but have a dual monarchy based on the Sparta of Greece. The reasoning is that politicians became too shortsighted, and they wanted leaders that were in it for the long haul. Not really sure a hereditary monarchy is the answer, but it is definitely true the politicians of current era are only concerned with the next short term election cycle.
This book does a brilliant job of showing how an army is built up from scratch. The mechanics of a Maoist type guerilla war. Starts with terrorist attacks and assassinations geared toward destabilizing the government. They hope to drive the government to more repressive measures which drive more people to the movement. This is also only sustainable with the help of an outside entity bankrolling it. Ends with an exciting battle and the Crown Prince Lysander the future first emperor making a bold move to win the battle. Although not decisively as there will be a return in the next book.
THE BOOKS THAT TIME FORGOT. 
Thats a pretty cool cover for this book. Great review