Because of nukes, China will still have to coexist with the west. There's no real point in planning for anything else. Unlike with the German nazis, we cannot just walk into the amerinazi cities and eradicate them.
But there are other ways than direct military to limit and destroy them. By removing them from being able to have any client states they can parasite off of, their purchasing power will crash and cause widespread suffering. The introduction of narcotics and promotion of corruption within their ranks will keep them down permanently.
Many of these are already natural developments in America. China just needs to accelerate them.
Coexistence doesn't have to mean acceptance. China can still declare war on America's way of life and tear it down, like America's ancestors declared war on China's way of life.