A friend of mine sent me this video the other day. It's called Prince of Peace God of War. I highly encourage you to watch it. The filmmaker, John Campea, interviews both Just War theorists and pacifists. My only criticism is--ironically-- that the Just War side wasn't adequately represented. Some of the arguments they presented were really grasping at straws, like using the story of Jesus cleansing the temple as a proof text that Jesus approved of His followers killing in war. Really???
Also, pay close attention to how Tony Campolo deals with the Nazi argument. The story he tells, which is the very last part of the film, is one of the most moving stories I've ever heard about the power of non-violent redemptive love identifying with the suffering of the world--the way of Jesus.