Quickly is relative. Realistically it might take years for them to fully replenish their stocks, but for planning purposes China cannot assume more than 48 months. Is China prepared to start the countdown on AR just yet? Maybe, but not for the sake of anyone else
Congratulations, you now have WWIII and have very likely tripped the US’ nuclear MAD triggers. And there lies China’s primary dilemma. To fight America directly will be such a momentous undertaking that anything other than total unconditional victory isn’t worth the cost. But total victory is impossible with MAD.
The solution isn’t China’s nuclear silo fields or SSBNs, but Star Wars (SW).
The only scenario where nuclear war is tolerable is if you have SW orbital ABM defences that has a credible chance of limiting the costs to something approaching acceptable.
This is where the hidden arms race is raging without the world even realising. This is why Starlink is so important and also why China is investing so much in mass launch capabilities. Because if one side can create enough of a lead on in mass orbital launch capability over the other, then they can rush deploy SW orbital defences. From that point on, it’s game over as they can and will shoot down anything from the other side trying to get into orbit, be it their own SW platforms or ASAT or ICBMs. That’s the only feasible way any side can break the MAD dilemma, and that is for sure more than 48 months away.
Short of being within sprint distance of such a paradigm shifting capability, I just don’t see China proactively seeking direct war against the US.