Autononous weapons capable of ending the world are old, yes.
Autonomous weapons capable of securing territory and resources, and personnel, that's on the way.
What might be interesting to think about is the prevalence of human controlled drones in warfare today, in various environments and climates as we currently speak. Right now they require a human to operate and identify targets or perform defensive maneuvering. All of this videography is undoubtedly being logged and used for training more autonomously controlled drones. Eventually an operator would just deploy a swarm at a sector akin to flagging it for an air strike, and drones would eliminate anyone or anything of interest there.
