But this all comes back to the self-interest and game theory discussion.

Let's suppose that, like you, both Moscow and Beijing do not want AGI to exist. What could they do about it? Why should they trust that the rest of the world will also pause their AI development?

This whole discussion is basically a variation on the prisoner's dilemma. Either you cooperate and AI risks are mitigated, or you do not cooperate and try to take the best outcome for yourself.

I think we can expect the latter. Not because it is the right thing or because it is the optimal decision for humanity, but because each individual will deem it their best choice, even after accounting for P(doom).