Unless this ban actually resembles something like global nuclear non-proliferation treaties, it would make absolutely no sense for us to cripple ourselves when someone like China continues full speed ahead.

I don't know what the solution is, but what I do know is almost nothing good will come out of _just_ the US pausing.

Unless he has an actual plan for effective global enforcement of his proposed policy, this is all just posturing at best, and a transfer of power to adversarial foreign states (that have no such moral qualms and worries around superintelligent AI) at worst.