China imports more oil than any other nation on earth. A majority of that oil originates in the Persian Gulf. The overwhelming majority of that Gulf oil moves through the Strait of Hormuz. This dependency is the most significant structural vulnerability in the Chinese economy, and Beijing has spent the better part of two decades trying to reduce it without succeeding in any meaningful way.

The arithmetic is unforgiving. China’s oil import dependence has risen, not fallen, as its economy has grown. Domestic production has plateaued and is declining at the margin. The non-Gulf sources that Beijing has cultivated — Russia, Angola, Brazil — are real but insufficient to replace Gulf supply. When analysts calculate what a thirty-day closure of Hormuz would do to Chinese industrial output, the numbers become politically significant very quickly. Beijing’s strategic planners know this. They treat it as the central energy security problem that has no clean solution.

India sits at the northwestern edge of the Indian Ocean, closer to the Persian Gulf than any other major Asian economy except China. This geography is an asset — shorter transit times, lower shipping costs, access to Gulf labor markets that have sustained remittance flows for decades — and a vulnerability. The same proximity that makes Indian trade with the Gulf efficient makes Indian energy security exposure to Hormuz direct and consequential.

Japan imports approximately 90 percent of its energy. It has no significant domestic fossil fuel production. Its nuclear power sector, which once provided a substantial share of electricity generation, has been operating at sharply reduced capacity since the Fukushima accident of 2011, with only a portion of the pre-accident reactor fleet returned to service. The Gulf supplies the majority of Japan’s crude oil, and Gulf LNG — primarily from Qatar — supplies a substantial portion of its natural gas. There is no combination of alternative energy policies or supply source diversification that changes the fundamental arithmetic on the timescale of months. Japan’s dependence on Hormuz is existential in a way that is not hyperbole.

South Korea is among the most energy-import-dependent economies of any significant size in the world. It has no domestic oil production, minimal natural gas reserves, and a geography that makes pipeline connections to alternative supply sources impossible. Its entire hydrocarbon supply arrives by sea, a majority of it from the Persian Gulf, and all of the Gulf portion transits the Strait of Hormuz. The country has built one of the world’s largest economies and most sophisticated industrial sectors on an energy supply foundation that is concentrated in a single maritime corridor controlled in part by a government that has expressed willingness to disrupt it.