The main factions are:

a local soviet council with soc-demmy tendencies reflecting the Soviets' canonically cooled-off relations with the US

Remnants of the Chinese government attempting to reunify an alienated eastern bloc before NATO can get back on its feet

A Makhno-esque black army that demands autonomy for the local people

The main driver of the conflict is control over a robotics factory that can be salvaged and converted into creating power armor

Later on you find out that the Enclave is stoking the fight by releasing capitalist super mutants, and the final climactic battle is set against a backdrop of a kaiju fight between Liberty Prime and a giant mechanized The Motherland Calls