They had some common and basic systems that included much of the last civilization, such as labor laws, tax systems, etc. But they also tried to adapt war, a system that no one wanted to reclaim. The name "Last World War" is to make sure that people dont experience the tragedy again. Now has a total of 10 Earths that sometimes have to work together, sometimes hostile. How to build the next stage of the world is not in the hands of you and your society.