The planet Victoria... was a prison colony, and all the people on it are descendants of either the prisoners or the wardens. The 'townsfolk' are peaceful, and committed to non-violence. The 'City people' are more brutal. The central theme of the story is the conflict between the Shantytowners and the City people, and the problem of staying true to a non-violent way of life in the face of oppression.
It's a little bit like Salt by Adam Roberts, but that novel is a lot more nuanced in presenting the two 'sides'.
The two men could hardly be more different, and the misunderstandings and errors mount as each tells his story in alternating chapters. Barlei (authoritarian) is completely sure of his own decisions, and rejects even the thought that he may have made a mistake. Petja (anarchist), in contrast, is ever aware that, in organizing and leading others to fight back, he is violating the basic principles of his society, becoming what his fellow anarchists refer to as a "ridgidist." Yet he believes that he is doing what must be done. Regardless of which character we might perceive as the most sympathetic, Roberts takes us far enough inside each for us to understand why they act as they do.
(links above are to reviews, from which the quotes were taken)
In The Eye of the Heron there's a scene where the pacifists have broken away, and trek off to find a new place to live. They all start arguing, and Le Guin is obviously trying to portray how conflict can be dealt with non-violently. There's one scene that sticks in my mind, which is that one of the pacifist women slaps another woman across the face. At this, the people listening to their discussion lose interest and wander off.
I think what Le Guin is saying is that our society encourages violence by being interested in it, and paying attention to it, which rewards people who escalate conflict. If we remove the reward, people lose the motivation.
I've always thought this was a very implausible scene, which undermines the whole story. Her noble/peaceful society depends on people behaving in a way they never would. In real life everyone would cluster round to see the fight.
Or would they? I'm as interested in violence as the next girl, but I actively avoid reading blogs where people spend the time attacking each other. It's a fine line, because brisk debate is good fun, but if it gets nasty it's boring.
And for this reason I think people have created havens (our corner of livejournal is a good example) where we attempt as best we can to handle conflict in a good-natured way. And the places where people behave in stupidly aggressive ways, well, I think they go into decline don't they?