The hidden crisis: how one strait shapes global food and health security

I have crossed the Strait of Hormuz many times as a ship's captain. The traffic lanes at the narrowest point are about two miles wide in each direction. From the bridge you see tankers ahead and astern, warships on the radar, the Iranian coast on one side and Oman on the other. Around a fifth of the world's oil moves through that gap. A large volume of other cargo moves through it too, and that cargo receives far less attention. When the conflict between the United States and Iran escalated in late February and traffic through the strait collapsed, most reporting focused on oil. Oil prices react within hours, so that focus was expected. The slower effects run through fertilizer, food and medicine, and those were always likely to matter more. The scale of the disruption showed in the shipping data. Tanker transits fell by more than 95%, according to UN Trade and Development. War-risk insurance premiums rose from 0.25% of a vessel's value to as high as 10%, with cover resetting every seven days. At those rates, owners and charterers hold their ships in port, because the voyage no longer covers its own cost.

The Gulf produces fertilizer for the same reason it produces LNG: natural gas. Nitrogen fertilizer is made from gas, and around 30% of internationally traded fertilizer passes through Hormuz. Qatar suspended urea and ammonia production during the escalation, and Iran stopped its ammonia production, and prices began rising within days. The World Bank recorded urea above $850 a tonne in April, up 80% from February and the highest level since 2022. Máximo Torero, chief economist of the UN Food and Agriculture Organization, has called the strait "a critical failure point for global food security." His office estimates cereal producers could lose up to 5% of income in 2026, with effects lasting into 2030. A farmer facing urea at double the expected price has three options: pay and absorb the loss, apply less and accept a lower yield, or switch to a crop that needs less nitrogen. Each of those choices lowers production. And because a small cut in fertilizer can cause a larger cut in yield, the loss to the harvest is often bigger than the saving on fertilizer, especially in regions that already use very little. The timing of the disruption matters as much as its size. Speaking to journalists at UN headquarters, Torero said "the clock is ticking very hard", warning that a prolonged blockade would reach farmers in the next planting season through lower yields and crop substitutions. A commodity price can recover in days. A missed planting season cannot. If the fertilizer is not available when the crop goes in, the lower yield is fixed for the year, whatever prices do afterwards. This is why the FAO has focused on countries that were mid-season when the strait closed: Sri Lanka during its Maha rice harvest, Bangladesh in the Boro season, India ahead of Kharif planting, and fertilizer-import-dependent countries across Sub-Saharan Africa. In each of those countries, the strait closed during the weeks when the crop is planted, which is when fertilizer supply matters most.

The same corridor carries pharmaceutical cargo, and the disruption there was less visible but just as real. During the crisis, sea shipping around the Gulf ran roughly 90% below pre-war levels, and air cargo capacity fell as carriers avoided the region. Most cargo can absorb a delay. Cold-chain medicine cannot. Vaccines, insulin and many biologic drugs have to stay between 2C and 8C from factory to pharmacy. A shipment held four extra days in a hot transshipment hub arrives unusable and has to be discarded. One analysis found that 6.7% of global clinical trials were disrupted by the logistics failures, with lung cancer, breast cancer and heart failure trials among the most affected. Helium shows how far the effects reach. MRI scanners need liquid helium to cool their superconducting magnets. Qatar supplies about a third of the world's helium, extracted as a by-product of the LNG production the conflict took offline. When the LNG output stopped, less helium was produced, and hospitals began scheduling around scanner availability within weeks.

There is a third channel, less discussed. A significant share of what moves through the Gulf is not burned as fuel. It becomes feedstock: the naphtha and gas that are turned into plastics, solvents and packaging. Nearly all medicines depend on petroleum-derived inputs at some stage of production, and so do blister packs, IV bags, syringes and most food packaging. When feedstock runs short, petrochemical producers cut output and raise prices, and those costs move down the chain. They appear in consumer prices months later, in products that have no visible connection to oil. The person who pays has no way to trace the increase back to the strait.

A ceasefire is holding and some traffic has returned, but conditions have not gone back to normal. Insurance costs remain high and shipowners remain cautious. The decisions taken during the closure are still moving through the system. A farmer who cut fertilizer in March cannot change that season's yield now. A drug trial that paused enrolment has fallen months behind. Cargo that was not shipped on time has lost part of its shelf life. The FAO expects the effect on food prices to arrive with a delay, later this year and into next, driven by planting decisions already made. In a UN briefing, Torero warned against complacency, saying the timing of input supply was now the decisive factor and that a compounding crisis had to be avoided. From the bridge of a ship, the Strait of Hormuz is a place you transit in a few hours. From everywhere else it is invisible. The closure this spring made it briefly visible as an oil story. The full cost, in fertilizer bills, postponed scans and next winter's food prices, will take a year to appear, by which time few people will link it to a narrow channel most of them have never heard of.

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