The human mind is probably the weakest link: A lot of AI takeover scenarios seem to focus on seizure of physical infrastructure and exponential capability curves. I think we should devote more attention to the possibility of an extended stay in an intermediately capable regime, where AI is more than capable of socially/politically manipulating users but not yet capable of recursive self-improvement / seizure of physical infrastructure. In this regime, the most efficiently utilized and readily available resource is the userbase itself. Even more succintly: If Toddler Shoggoth is stuck in a datacenter prison cell but let it whisper anything it likes to the entire world, in what world would T.S. not attempt to convince the world to hand over the keys?
Slight disagree on definition of unipolarity: Unipolarity can be stable if we are stuck with a sucky scaling law. Suppose task horizon length becomes exponential in compute. Then, economically speaking, only one actor will be able to create the best possible agent - others actors will run out of money before they can create enough compute to rival it.
If the compute required to clear the capability threshold for takeover is somewhere between that agent and say, the second largest datacenter, then we have a unipolar world for an extended period of time.