The Liberation of Earth

The Dendi are otherwise uncommunicative, except at one point when they tell humans to abandon the area of Washington, DC, where they set up a huge building which is later learned to be a recreation hall.

The Troxxt arrive and a battle breaks out, killing one-tenth of humanity before the Dendi flee into space; Marseille is destroyed by rocket exhaust.

The Troxxt are the leaders of the carbon-based-lifeform resistance against the silicon-based Dendi, and invite humanity to join them in their great crusade to free protoplasmic life.

After killing any human who collaborated with the Dendi (which includes most high-ranking government officials), they work thousands to death in industrial projects.

Eventually what remains is a cinder of a planet in an elliptical orbit, slowly losing air, abandoned by both Troxxt and Dendi as it is no longer safe enough for their soldiers.