China buys Russian oil via pipeline and tanker, so they’re not entirely dependent on Gulf crude. They also have more levers to pull at the state level to reduce civilian demand on petroleum. Along with current electrification/alternative energy efforts, that could be a significant reduction in demand. Finally, China has operated nuclear subs for decades, and is actually building a nuclear aircraft carrier. China likely does not think it can compete head-to-head with the US in a conventional naval confrontation, and has invested heavily in missile and drone technology, along with other asymmetric capabilities. It would certainly be painful if the US took over the Persian Gulf, but likely not debilitating.

I did find it interesting that in both Venezuela and Iran, Chinese radar and air defense did not hold up so well, but they’re at least getting a lot of real world test data from it.