That doesn't exactly limit the impact of cutting off the supply. It's a global trade market. If China buys on the global market from other places instead of Iran because that oil isn't available, that still creates a shortage for everyone and that still pushes up the price of oil for everyone.
Sure. But the US has substantial domestic production. So China (and everyone else who has to import the majority of their oil) gets hurt more.
Short term, you might be right.
However... higher oil prices also increase energy prices across the board, and China's energy sector is dominant in renewables. I think they're more than happy to have the competing energy sources become even more expensive.
...and of course the US has a lot of other industries that are hurt by this: https://www.npr.org/2026/03/26/g-s1-115240/iran-war-strait-h...
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