Most of these comments have nothing to do with the topic at hand, which is the general questions of "what justifies war" and "what is a true peaceful world?"
A lot of this is based of the fundamental questions of what is right and wrong, the escalation of force, and the position of human relation to the universe versus human perspective of that.
Instead of making this post longer, I'll simply say what I consider good and evil is: the experience of life and what goes against it. Anything that allows human to experience life and which allows life to continue is known as good in my terms. While just the opposite is what I consider evil, the prevention of life to continue and the prevention to experience life. And my ideas are not limited to "human to human interaction" but to interactions of all living things with each other.
Now then, humans by nature will always create and/or destroy. But consider this as well: everything from nature does so as well. Fire is capable of construction and destruction, but we never call it an evil thing. Water, wind, earthquakes, etc. When nature destroys, we don't call it evil, nature is nature. But we forget that humans are from nature and that we too do the same. It is our personal opinions that determine what we call evil or not, or in other words our emotions do. How we feel about things makes us label them.