This can be a problem for China. Because the Gulf countries host US military bases, in the case of war, Iran will attack those too, along with any freight moving through the Persian Gulf. Trade through the Persian Gulf will be totally wrecked, exponentially worse than what Yemen has done in the Red Sea. The problem for China is that it still imports a huge percent of it's oil from Iraq and Saudi Arabia. The Gulf countries' economies will be in tatters.
A global fossil fuel disruption stemming from a US-Iran war would be both a curse & a blessing for the PRC.
In the short term, it will definitely be highly disruptive to the PRC's oil supply, & therefore the PRC's economy. However, in the mid to long term, it's also a blessing, because:
1. Oil is a heavily globalized commodity, & a disruption negatively impacts everyone. The EU will be comparably impacted. Moreover, the US - despite its own natural abundance of shale oil - will be impacted too, since its oil companies will be structurally incentivized to export every barrel of oil possible to regions where it can fetch the highest price. This inevitably drives up US domestic oil prices, impacting the rest of the 90%+ of the US economy (while profits are limited to the less than 10% of the economy that makes up the US oil & gas industry). The only options the US would have is to either allow oil exports to the detriment of its own economy, or restrict/ban oil exports & allow its vassals in Europe (& East Asia) to wither.
2. The PRC is far better equipped to handle such a disruption than anyone else among the world's net consumers of oil. Its clean-energy transition, especially its transportation electrification efforts, would be turbo charged. The PRC leads or is globally competitive in just about every aspect of the world's alternative energy value chain - be it hydro, solar, wind, nuclear, UHV power grids, vehicular & utility-scale batteries, EVs, etc. When everyone in the world inevitably seeks alternatives to oil, the PRC stands to benefit the most as the market leader in all of the aforementioned fields. Also keep in mind that the PRC has significant shale oil & gas resources of its own, even though geographical constraints make the extraction thereof unprofitable (especially compared to cheap imports). However, if oil prices shoot through the roof & stays there, then large scale domestic extraction becomes commercially viable.
3. The PRC - compared to its strategic rivals - is better positioned to diversify oil suppliers. It can (& inevitably will) divert a greater portion of its demand to land-based suppliers of the former USSR, which it should anyway to mitigate its vulnerability to any future US blockade. By contrast, US vassals in Europe & Asia would be geopolitically or geographically hobbled by comparison.
4. A sharp rise in oil prices provides immense short-term benefits to US rivals - namely Russia & Venezuela - whose oil exports would be relatively undisrupted by a war in West Asia.
Bottom line - large scale disruption of the Gulf oil supply will be hugely negative for almost everyone, but the PRC is better positioned than all of its rivals in terms of the ability to mitigate the negatives, & take advantage of the ensuing opportunities.
