The Russo-Sino Alliance was an old-Earth superpower formed from the ancient national states of China and Russia. After years of co-operation against the western superpowers, the RSA was eventually formed in response to the formation of the United States of North America, and their subsequent alliance with the United European States. During the Fossil Wars, in retaliation to a USNA invasion of Siberia, the RSA would achieve major military victories against the USNA and eventually the UES, with nuclear bombing of Alaska and the invasion of Europe.

Eventually, the RSA would ratify the Treaty of Humanity with its former enemies, and begin its own project to leave the dying Earth, whose descendents would pass through the Shifted Wormhole in Sol and eventually form the Phoenix Republic. Seperatists who remained on Earth re-united the stricken civilisation and formed the Central Earth Government.

In a twist of fate, both descendents of the RSA would become major allies against thier ancient, former enemy, now entrenched in Aquarius as the most powerful state in human history, the UTN.