Available in the Anarchist Library.
In a future where all green life on Earth has been destroyed, the human army travel to an alien world of forests and enslaves its people to harvest lumber. The indigenous people, normally a peaceful society led by the visions of dreaming men and the direction of practical women, fight back viciously and overcome the soldiers — but knowing such violence, how can they return to their peaceful lives?
A beautiful, brief and very difficult book: my copy begins with an essay by Le Guin on how the story became a "preachment" in light of her opposition to the Vietnam War, and asks if it's moral for an author to exert such influence over others and preach through their stories.