In the first half of the 21st century, humanity faced another problem: it was running out of easily obtainable energy resources. While the Earth still held plenty of fossil fuels, their exploatation was becoming less and less profitable. Various economies reacted differently to this, but they all started capitalizing on renewable energy sources. Unfortunately, as the oil kept drying out, the world peace suffered too: many small but wealthy countries that weren't on good enough terms with one or other superpower became subjected to exploitation and aggression.