More International trade reduces conflicts within the International system because it facilitates trust and teamwork between a variety of countries. Over time this will reduce conflict because more countries will be relying on each other. It will also help in my opinion because more countries will also respect each others boundaries more too.
One of the major factors creating conflicts in the world is a lack of resources that are available in developing countries. By its very nature trade brings additional resources to areas of the world that are in need and as their economies stabilize the conflict that lack creates is reduced. Prosperity usually reduces conflict as those who would use force to get resources begin to find other ways to gain them than force.