What if there are trillions of AI's competing?
Harry Harrison wrote a SciFi story back in the '60s or '70s that considered a world where a malfunctioning drone ended up sparking random evolution of electromechanical systems on a distant planet, and a global ecosystem of machines arose, each species interacting per evolved behaviours just as we bits of mud do.
There are many ongoing efforts to create AI, and many are creating multiple AI's. It is hard to envision but one AI coming to completely control everything and everyone. What kind of war would that entail?
Edit: IIRC the story was 'The Stainless Steel Rat'.
All of that is completely new to me, AFAIK.