They're going to need a lot more reeducation camps for that.

Between "Pax X" and "Pax Y", there's often a war. The war leaves X weakened to the point that they can't enforce "Pax X" any more. Pax Americana ending probably won't just be because Pax China peacefully superseded it.

*Pax Sinica if we want to be consistent with our Latin analogizing.