The basics first, because the rest of this doesn't make sense without them. The Strait of Hormuz sits between Iran and Oman, connecting the Persian Gulf — where Saudi Arabia, Iran, Iraq, Kuwait, and the UAE all ship their oil out — to the open ocean. The Red Sea is a different body of water entirely, the corridor between Africa and the Arabian Peninsula that ships use to reach the Suez Canal and, from there, Europe; its own narrow southern exit, the Bab-el-Mandeb Strait, sits next to Yemen. Yemen is a country at the southern tip of the Arabian Peninsula, about 34 million people, in civil war since 2014-15, when the Iran-backed Houthi movement seized the capital and a Saudi-led coalition began fighting them. The Houthis' actual missile, drone, and Red Sea ship attacks escalated sharply once Israel's war in Gaza began in October 2023. OPEC is a cartel of oil-exporting countries, mostly in the Middle East, that meets and agrees on how much oil to pump — one of the ways the price of oil gets set worldwide.

The part that seems like it shouldn't be true, but is. The United States pumps more oil than any other country on Earth — about 13.6 million barrels a day, roughly 40% more than second-place Saudi Arabia. And American gas prices still rise when a war disrupts shipping through a strait most of that oil never sails through. The reason is that oil isn't sold like a local product with its own separate price in each country — it's one global commodity, priced on one global market. When Gulf supply gets threatened, the price of every barrel on Earth goes up at once, including the barrel already pumped in Texas, because buyers will pay international prices for it regardless of where it came from. Being the world's biggest producer doesn't opt a country out of a global price; it just means more of the profit stays home when prices rise.

At its narrowest, the Strait of Hormuz is about 21 miles wide, with a shipping lane in each direction only about 2 miles across. Through that gap moves roughly 20% of the oil the world consumes — about 21 million barrels a day — and roughly 20% of the world's LNG trade, including 93% of Qatar's and 96% of the UAE's gas exports. This piece isn't about who's winning the war currently affecting it; wars along this coastline have started and ended before, and the strait's width hasn't changed. The actual story is why a 21-mile gap carries this much weight, and why disruption to it shows up in an American's life within days.

Oil is the obvious piece. Fertilizer is the one that actually decides who eats. Natural gas is the primary feedstock for ammonia, running 70-80% of production cost — so the same Gulf states that export oil also produce a disproportionate share of the world's nitrogen fertilizer, and roughly half of global food production depends on synthetic nitrogen to grow at all. The current disruption has already suspended about 3.9 million tonnes of Gulf fertilizer exports since late February 2026 — 30% of the region's annual total. Urea prices rose 46% in a single month; the World Bank projects fertilizer prices up 31% for 2026, the least affordable since 2022. East Africa draws about a third of its fertilizer from the Gulf, the single most exposed region on Earth for this input, and India's IFFCO has already begun cutting domestic urea production because the imported gas it needs as feedstock is now too expensive. This isn't a future grocery-price story for an American reader — it's a present-tense planting-season story for two of the most food-insecure parts of the world, happening in parallel with whatever shows up at a US pump.

Nitrogen isn't the only fertilizer leg, and the other one has nothing to do with the Gulf. Crops need potassium too, and the US has almost none of its own: Canada holds more than a third of the world's potash reserves and supplies 80-90% of what American farmers actually use, nearly all of it mined in Saskatchewan. It normally crosses the border tariff-free under the US-Canada-Mexico trade agreement. This year it hasn't — a 25% tariff on Canadian potash, later cut to 10% after pushback from US farm groups, is a policy choice with no foreign war behind it at all. Building new domestic potash capacity takes 10-15 years, so there's no fast substitute if the relationship sours further. Put the two legs together: nitrogen fertilizer is exposed through a war in a strait most Americans couldn't find on a map; potash is exposed through a trade dispute with the country next door. Different causes, same lesson — a food system that looks domestic and secure has real foreign chokepoints running through it either way.

The part an American actually sees. Wholesale and pump prices in the US move together with about 97% correlation, and the US passes international price changes through to drivers faster than almost any other major economy, because fuel taxes here are a smaller share of the pump price than in most of the OECD. Only about 7% of US crude imports actually flow through Hormuz directly — most Americans have no physical supply line running through that strait at all. They feel it anyway, because oil is priced on one global, fungible market: a barrel disrupted in the Gulf raises the price of every barrel everywhere, including the ones already headed to a refinery in Texas. Not "a war is happening over there," but "the price is set globally, and the pump is where that global price becomes personal, usually within days."