They could roll out next-gen LLM-powered disinformation/agitation bots and rapidly turn people across the world against their neighbors over all sorts of locally-contentious topics—and LLMs are capable of accounting for that context.

Why do most of the dirty work with physical (autonomous) weapons when you can just get your “enemies” (us) to kill each other? Then it’s just a matter of mopping up. This doesn’t even necessarily take a massive conspiracy, either, as it’s a lot easier to covertly “stockpile” computing power + bandwidth than to stockpile drones or other autonomous weapons.