~100% of Apple's manufacturing depends on China continuing to permit hundreds of thousands of Chinese nationals in Chinese factories (Foxconn's plants in Zhengzhou and elsewhere) building Apple products.
I'm not sure what you mean by "knuckle under" in this context, but Apple is, today, wholly dependent upon Taiwanese and Chinese manufacturing (for chips, and assembly, respectively).
If there is a war between China and Taiwan, or China and the US, Apple stands to lose the most of any single organization, I think.