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.