I just read an excellent post by Simon Barrow from Ekklesia on the challenge of peacemaking in our time:
So after Christendom we are called to reassess in a core sense what it means to be church, to be that body; what is means to be a peacemaker rather than just a refuser of war (a passivist); what political realism looks like in the face of Christ, rather than in the image of the Imperial Order and its realpolitik.
You can read the full post here.