I would choose Peace everytime on a global scale because war is result of conflicting versions of reality, e.g. my god and 'truth' versus your god and 'truth'. Truth is too flexible to be an absolute in a social sense.
This is a tough question because I'm at a loss to rationalize how people would behave if they realize an ultimate truth. Ideally, knowing would remove causes for fighting, but I think some people are happier living in partial ignorance. Something to ponder.
In regards to a society, peace can be an easily imagined scenario. But what a truthful society would look like is very ambiguous. Would people tell the truth all the time? Would everyone work towards understand or something? But I guess I'd still choose truth because however it would look, it would be good.