My opinion may sound crazy, but it's really just what I think.
Violence rates are very low, as bisjac said. A utopia, where everyone gets along, would be boring. Really. When people get bored, they fight. Start a war, maybe.
Therefore, violence is sort of a good thing. It not only keeps us advancing our defensive systems and technology, but we also learn to be more careful every time something bad happens. But something bad will always happen, given time. Count on it.
A teaching that I have adopted into my philosophy is that both our good and bad actions are helpful to others. The person who first told me this put it this way:
Say you have a bowl of dirty potatoes. If you shake the bowl, it seems like they are violently banging against one another; but what's less apparent is that, as they hit, they knock the dirt from one another, becoming clean.
This doesn't mean I think we should intend to do bad things, or be violent. But I don't necessarily think it should be put to a complete halt, either.
