Why is history so violent

What should the christian's stand be concerning military involvement? is there ever justification for war? can a war ever be "just"? write your answer in a paragraph of 125 words.

Yes the notes gathered in your research to answer the following questions

Which concept is plato expressing in the excerpt below? when men have both done and suffered tyranny, and have had experience of both . . they think that they had better agree among themselves to have neither. . —plato, the republic: book ii