After the Tannia/Erde war has ended, a veteran of the beaten Erde space force lives as an instructor on Tannia. It is forbidden for him to fly ever again, but when the third human colony in the system attacks both Tannia and Erde, the situation changes. Coming out of retirement, he tries to mobilize forces on his homeworld to fight back the occonian invaders. But something isn’t right with the Occos, something strange is going on, and soon he finds out when he finds himself as a prisoner on Occo.
It’s a great mix of character study and military SF (with a hard SF approach to space fights). The plot that has some ingenious twists and always plays with the expectations of the readers. When you think you know everything that will happen next, you might, or not. But where the book really succeeds is in bringing the characters to live, the Erde veteran, his Tannian love interest, the Occos, and many others.
One of the things the book shows is the dire effect of the influx of too much new technology into a culture that isn’t adequate to absorb it without harming its own culture in the process, and while I question that this is true for every instance, it’s hard to argue that there might be cultures that can fail at doing so. The solution to this problem in the end is quite drastic, but understandable from the POV of the Tannia/Erde alliance, but I do wonder whether they will allow the Occonian culture to grow at their own pace, or completely preventing them from ever growing at all.