Crossfire
by Nancy Kress

Description:
Crossfire is the story of a human colony settling on a distant planet, a colony formed by Jake Holman - a man trying to escape a dark past. But as this diverse group of thousands comes to terms with their new lives on a new world, they make a startling discovery; primitive humanoid aliens. There are only a few isolated villages, and the evidence seems to indicate the aliens aren't native to the planet - even though they live in thatched huts and possess only primitive tools. When the humans finally learn the truth, they find themselves caught up in an interstellar war. In the end, a handful of human colonists will have to choose sides in the struggle. A lot is riding on their decision - not just the fate of their new home, but the fate of all humanity.