Upward Sweeps in The Historical Evolution of World-Systems
New systems theories in international relations should study human interaction networks over very long periods of time (since the Paleolithic) and the interactions between the human systems and biological and geological systems in order to comprehend and explain the patterned changes of the past and the possible futures for humanity. World-systems are whole important human interaction networks including relations among polities, trade and communications networks. Human social evolution is about the rise of larger and more hierarchical and more complex societies and the growth and intensification of long-distance interaction networks. This paper outlines a research project on the growth/decline phases of cities and states since the Iron Age in order to comprehend the possibilities for future global state formation.