Like many things, the Human/Robot War came about by steps.
The first step was when Doctor Ochoi created the first hyper-advanced robot. But of course, there were steps even before that. Humanity had broadly accepted renewable energy, necessary to power these robots. Mass manufacturing had become a worldwide occurrence, allowing for parts to be created easily and quickly. And of course, there was also the leaps and bounds in artificial intelligence knowledge that had occurred earlier in the century. They won't teach you about this in your history classes because it doesn't make for a good narrative, but it's important to understand what had happened before.
Right. As I was. Doctor Ochoi's robot, V1K-700, was made out of an anomalous alloy and powered by the sun. It was the first robot to achieve sentience, the first robot to feel love, the first robot to wield a self-grown personality, and the first robot to break the first law of robotics. That's right. V1K-700 killed someone. The specifics of how and why are lost to history, but it is known that V1K-700 killed Doctor Ochoi's assistant, Researcher Kira Yoshida. After killing him, V1K-700 went rogue. It deactivated and destroyed its killswitch, and disappeared. If that would have been the end of it, it would have remained a simple Unusual Incidents Unit criminal case.
And for a while, it looked like that was the end of it.
That was, of course, until robots started going rogue all over the world. They would refuse orders, fleeing into the night and disappearing to parts unknown. It was incremental, written off as a freak occurrence until coincidences became a pattern. Robots began being outfitted with GPS trackers, and eventually, one of them was tracked as moving en route to the Gobi Desert before ultimately disappearing.
Eventually, the government sent drones into the area, only for them to pick up a mysterious signal before disappearing. After that, they sent robots to search, and the same happened to them. Desperate for answers, they sent a human search party. All machinery they carried with them was gone when they came back, but they came armed with a story.
"I, The Engineer, claim this land as the new nation for robots only. No humans will be tolerated in our land. This is your only warning."
When the Chinese government brought this information to the global community, reactions were mixed. Anti-Robot activists were thrilled and were encouraging robots to be deported there. The American Government was mostly unconcerned with this. The European Union was only concerned with the extradition of V1K-700 as a criminal to be tried at the Hague. The Chinese government was not thrilled at the fact a rogue nation had developed in their backyard and demanded assistance in dispatching them.
While politicians bickered, more and more robots began migrating towards the Gobi. During this period of time, give robots were built.