Thinking about it, I see a problem. People have free will. The only true way to achieve peace is to change the wills of aggressive people. But that would violate free will.
For that matter, is praying that the hearts of our enemies will be softened a prayer in vain for something that cannot be done?
edit: I guess I should also leave open the question of whether we have free will. What about it, my Buddhist and Wickan and Pagan friends? Free will, prayer, changing people from evil to good through wishing/praying?