In Island of the Blue Dolphins, violence always leads to more violence. The Aleutian hunters kill the otters of the island, and then massacre the people living there. Think the two events aren't related? Think again. This kind of violence points to a deadly worldview. The society of the island, after all, is almost wiped out.
Our protagonist, Karana, must figure out a less destructive way to solve conflict. How can she interact with those around her? How can she connect with people and animals that are so different from her? The novel follows many incidents where Karana's ideas about violence are challenged and changed. She eventually comes down on the side of pacifism (anti-violence), as she finds new ways to deal with the world around her.
Violence is part of the natural order of the world. It's destructive, but inevitable.
Violence is not acceptable when it can be prevented.
Violence is an effective way to solve conflict.