The recall went badly. United Systems Military personnel were involved in several pitched battles with their physical and mental betters. Due to their sheer numbers, however, the USM was able to storm many android strongholds and render the machines harmless. A month after the recall had begun, there were no androids remaining within the Earth system.

The USM now proceeded to purge the androids in other systems. At first there was cautious support from the provisional governments of the near colonies. However, as the purge continued into early 2379, the androids found an unlikely ally in the authorities of the outlying Outer Rim colonies. These were often new colonies, where life was harsh, and androids provided an essential service. Several systems banded together and sent a petition to Earth to bring their concerns to the USAll’s attention. It was ignored.

The simmering crisis was brought to a head in late 2379 at a planet several parsecs from Earth to which many androids had fled seeking sanctuary and asylum. They were welcomed by the native miners, and proved a boost to production. Here humans fought beside androids. Both met with the same hostility from the occupying USM forces. The matter had suddenly escalated.

Androids had also been gathering on those far colonies of the Outer Rim. The governments of these systems were fully aware that USM forces would reach them eventually and would show as much restraint with them. Twelve adjoining systems sent word to the USAll that they would resist movements they considered in contravention of local law. The USM ignored them again and sent the ships anyway.

Formally declaring themselves the Confederation of Allied Systems, or CAS, the twelve systems announced their breakaway from the USAll, and called upon other Outer Rim systems to align with them. They gained a thirteenth member, though most remained cautious and dubious. It was only after that first surprisingly successful, defence that many others allied with them.

As 2379 led into 2380, the galaxy erupted into Civil War.

NOTES:
The auton recall is mentioned in passing in "Alien: Resurrection", but I've elaborated on it and thrown in a galactic civil war as well. Sure, that's not seen in the film, but it's not contradicted, either. The pretty obvious analogy here is the American Civil War, in which the United States split over the issue of slavery. Here, the slaves are robots rather than black people. I like writing stories set against a backdrop of war, without ever focussing on the fighting itself. At the time of writing this I was also researching the American Civil War for a story about a Native American freedom fighter-type hero liberating slaves.