The notion of China enterring an arm control treaty negotiation is a WISH by the US, there is no tinnest indication of China even picked up this talk. Any discussion, analysis and prediction based on this assumption is a wishful thinking and does not worth pages of posts. If China seeing 1000 nukes being a waste of money, China will not make that many in the first place, China don't need anyone to tell her to stop. If China sees the necessity of 2000 nukes, China will make it especially if her enemy asked her to not to do so. For the US, if it can afford to keep up the race, go ahead to make 10000 like Trumps 200% tariff, wiping off the earth for 100 times is no worse than 10 times as far as everybody concerns. If the US can not afford the game, then shut up, stop whining like a baby.