I will try and answer a very complex question, and by no means is this answer definitive. Due the process of industrialization (the move from an agrarian socioeconomic model to goods, manufacturing, and services model) makes for a very capital intensive model. Part of that. The dependency on fossil fuels such as petroleum/oil (as well as the energy policies of nation states) leads to secure resources through not only diplomacy. This is a world of limited resources, and fear of resource depletion is a powerful incentive.
