The centaur-like, predatory Posleen threaten a peaceful galactic confederation, to whose member races violence is nigh unthinkable. Finally, the dominant Darhel decide to enlist Earth against the Posleen—meaning that humans will do most of the fighting, the galactics having only relatively ineffectual artificial intelligences capable of battle. Why should Earth get involved? Well, a Posleen invasion fleet, already heading for Earth, will arrive in five years. With their advanced science, the relatively belligerent Darhel supply devastating new weapons, fighting suits, spaceships, AIs, and rejuvenation techniques so that aging vets can be drafted into the struggle. Three main storylines unfold. A squad of highly trained and experienced specialists departs for swampy Barwhon, newly conquered by the Posleen, for an intelligence mission. A huge but poorly trained multinational army lands in the deserts of Diess IV to try to stem a mighty Posleen invasion. Meanwhile, back on Earth, the few experienced soldiers that remain must fight to prevent a social and military meltdown. Nobody yet realizes that the Darhel fear humanity almost as much as the Posleen and will resort to underhand tactics to preserve their ascendancy. Antagonists battle furiously: human against alien, politicians opposing the military, and military old guard resisting the new order.
Ringo lays on the military style with a trowel, but the scenario's sound, with plausible consequences and action that never falters. A spirited, gripping debut: stay tuned for sequels.