Well... it is not an easy process, in order to bring about peace, once also has to bring about a wee bit of fairness. We can't keep accepting extreem poverty as the cost of our wealth. Further, there is not a single monolithic primitive culture, there are many different cultures warlike and peaceful in the past and present, I tend to think of large industrial states which don't have the intelectual advancement to figure out a better way of dealing with conflict than war as being primitive, but that is a term I use with some caution.
Cheers, Larry