Violence and Oppression

I am new to this site, this is only my second post, and I had some thoughts about Violence and oppression. I didn't know where exactly to post this, if this is not a good place please let me know.
The other night I had this dream where I came across the path of the Buddhist monk Thich Naht Hahn. We had a brief discussion, and he basically told me that all violence that exists in the world is the result of oppression. That if no one felt oppressed, there would be no violence. When I think of this rationally it appears to be untrue, people can be violent whilst competing for resources for example, but there does seem to some truth in this statement. Feel free to tear this idea apart, but I was just wondering what you guys had to say about it.