The Jet Fuel Cliff: Six Weeks After the Strait Closed

The ceasefire came on April 7. The 40-day threshold the FAO Chief Economist identified as the point at which farmer behaviour locks in for two harvest cycles was crossed on April 9, two days into the ceasefire window. The food security consequences of this war are already written into harvests that have not yet been planted, regardless of what happens politically next week.

A month ago I wrote a piece called "What If the Strait Stays Closed?" that argued the planning assumption for the humanitarian system should be a Strait of Hormuz that stayed functionally closed for weeks or months, not days. Six weeks later, the strait is still not commercially open. The 40-day threshold has been crossed. Transfer values across five fragile contexts are operating against an outdated baseline. And the jet fuel buffer that has kept commercial aviation flying through the war is about to start binding in the second half of April, which is to say this week.

This morning the Mercy Corps Crisis Analysis Team published The Long Reach of War : The Middle East Conflict's Economic Impact on Fragile Contexts, a flash report led by Holly Topham and her team that documents how the war has actually landed on five crisis-affected countries. I worked alongside Holly and the Crisis Analysis Team over the past week to contribute to the analysis and drafting. The paper is the substantive evidence base for everything I argue below, and you should read it in full here: https://www.mercycorps.org/sites/default/files/2026-04/the-long-reach-of-war.pdf

What follows is my own honest accounting of what landed from the March call, what the new evidence base shows, and one finding from a separate piece of work I have been doing in parallel that humanitarian logisticians need to be acting on this week.

What I called, and what landed

The biggest call from the March piece was that the energy shock would transmit through fertiliser to harvests, and that the people who would absorb it were the smallholders making fertiliser decisions in the active East African and South Asian planting windows. I had the chain right. Natural gas is the primary feedstock for nitrogen fertiliser through the Haber-Bosch process. Hormuz closure took approximately 30 per cent of global nitrogen fertiliser exports out of the market. Multiple major producers halted or curtailed operations. Global urea prices rose approximately 68 per cent. The FAO Food Price Index reached 128.5 points in March, its highest level since September 2025. But the timing was sharper than my March piece quantified, and this is the part that matters most. The FAO Chief Economist has stated that conflict beyond 40 days triggers farmer behavioural responses that carry through the 2026 and 2027 harvests. The Somali Gu, Ethiopian belg, and Pakistani kharif planting seasons are active right now.

The second call was that the strait would not reopen quickly, and that the closure would be financial more than military. That call held. The Mercy Corps paper documents commercial shipping through the Strait of Hormuz collapsed by approximately 94 per cent during the war period, from a pre-war baseline of 84 vessels per day to an average of five. Six weeks. Not days. The 7 April ceasefire did not reverse it. On 11 April, four days into the ceasefire, only 17 vessels transited in a single day, still roughly 80 per cent below the pre-war baseline. On 12 April, following the collapse of talks in Islamabad, President Trump announced a US Navy blockade of the Strait of Hormuz. The commercial reopening I argued was unlikely under the conditions I named is now further from reach, not closer.

The third call was the asymmetric pass-through to households absorbing the shock. Mogadishu fuel prices rose 150 per cent within days of the war beginning. Myanmar diesel prices rose by more than 55 per cent and irrigation costs doubled. In Ethiopia the shock moved beyond price into physical fuel unavailability, with the government issuing a formal rationing directive. In Sudan, the purchasing power of an April 2025 humanitarian cash transfer has eroded by approximately 40 per cent before food basket inflation is even counted. Retail prices in import-dependent economies follow global benchmarks up within days but lag significantly on the way down. Populations already absorbing the shock will continue paying war-era prices long after the headlines move on. That call held, country by country.

The honest part. I wrote on March 7 that the structural conditions for a rapid ceasefire were not present. A ceasefire was announced on 7 April, six weeks later. The right framing in March would have been not "the strait will stay closed because the war will continue" but "the strait will stay closed regardless of whether the war formally ends, because the conditions required to reopen it commercially are not the conditions that produce a ceasefire." That is the framing the Mercy Corps paper now makes explicit. I had the conclusion right and the reasoning slightly underspecified.

I also have to be honest about the remittance shock. I called it in March as the safety net nobody talks about and the most under-analysed transmission channel. A month later, it is still under-analysed. I do not have new evidence to either confirm or refute the call. The migrant labour and remittance flow data lags by months and the picture from this period will not be visible in the official statistics until the second half of the year. The call is open. I am still tracking it. If anyone reading this has visibility on Gulf labour markets or remittance flows since late February, please get in touch.

What the evidence now shows

The Long Reach of War documents how the war has actually landed on five fragile contexts. Somalia, Sudan, Pakistan, Ethiopia and Myanmar. None are party to the conflict. All are absorbing it through three specific transmission channels: fertiliser, diesel, and commercial shipping. The paper is the substantive evidence base for everything in part one above, and it goes considerably further than my March piece could from London-via-Paphos.

Three things in the paper go beyond what I could see a month ago.

First, the country specificity. The March piece talked about transmission to the people at the bottom in general terms. The Mercy Corps paper documents five specific country exposure profiles, each with a distinctive lead transmission channel. Two of the five country cases are worth dwelling on because they show the transmission mechanism most cleanly.

Ethiopia is the case where the shock moved beyond price into physical fuel unavailability. Ethiopia's vulnerability is structural: a single trade corridor through Djibouti, over 90 per cent of its fertiliser sourced from Gulf producers, and a belg planting season that is active right now. When Hormuz closed and Djibouti's capacity to receive and process fuel shipments partially failed, there was no alternative route at scale. The government issued a formal rationing directive during the war period. This is what it looks like when an energy shock hits a country with a single corridor and no buffer: not a price signal but a physical shortage that forces the state to ration what little it has.

Somalia is the case where the dollarised import-dependent economy means there is nothing standing between a global price spike and what a household pays. The shock transmits directly, without the buffering that a local currency can provide in other contexts. Somalia imports 60 to 70 per cent of its cereals and nearly all of its refined petroleum products. Mogadishu fuel prices rose 150 per cent within days of the war beginning, with transport up 60 per cent and water costs doubled in drought-affected areas. Transfer values were already covering only 70 per cent of the minimum expenditure basket before the war. The Gu planting season is underway. The collision with Hajj 2026 in late May creates additional pressure on Somali livestock export routes during the peak pre-Hajj demand window.

The other three cases extend the same pattern through different mechanisms. Sudan: another weight on a fractured war economy that was already collapsing under the world's largest displacement crisis, with the purchasing power of an April 2025 humanitarian cash transfer already eroded by approximately 40 per cent before food basket inflation is even counted. Pakistan: Qatari LNG routed through Hormuz arriving at the worst possible moment for the kharif planting season, with the current six-week window determining October and November harvest outcomes. Myanmar: irrigation costs doubled and diesel prices up more than 55 per cent, compounding on an energy depletion picture that was already deteriorating before the war.

Across the four standalone Humanitarian Response Plans, 57.5 million people are already in acute humanitarian need against a combined requirement of $4.7 billion, funded between 12 and 26 per cent. Including Ethiopia under the Sudan Regional Refugee Response Plan, the total reaches 60.1 million people.

Second, the operational decision points. The single most immediate implication for cash and food security programming is transfer value revision. Cash working groups in all five countries should be recalculating the minimum expenditure basket against the post-war cost base before mid-May. Any country where this has not happened is one where transfer values are operating against an outdated baseline and the purchasing power erosion documented in the paper will continue to land on the people least able to absorb it. Food security actors should track retail-level fertiliser availability in the active planting-window countries over the next four to six weeks, because the pass-through from global urea prices to local agrodealer retail is the earliest observable signal of whether the production-side shock is reaching farmers. Logistics planners should build continued elevated Gulf routing costs into Q2 and Q3 2026 planning, because the commercial shipping constraint will not resolve on a political timetable. These are not future planning items. They are decisions for this week.

Third, the forward-looking indicators. The paper names specific monitoring thresholds that can be checked against reality in a month. Hormuz transit volumes (a sustained rise above 20 vessels per day would indicate the permission-based regime is easing, sustained below 10 would indicate it is formalising into the new operational baseline). Urea retail prices in planting-window countries on a four-to-six week pass-through window. MEB updates by mid-May. Iranian state messaging on the transit regime. Houthi posture at Bab el-Mandeb. The FAO Food Price Index April release. These are testable indicators that let analytical work be checked against reality rather than left as untestable assertions. The sector needs more of this. The Crisis Analysis team has done the work to provide it. Go read it.

The jet fuel cliff is this week

Now the part of this piece that is not in the Mercy Corps paper, because it sits outside the humanitarian transmission frame the paper was built around. I have been working in parallel on a separate analysis of how the 2026 oil shock is transmitting to Western economies and central banks, and there is one finding from that work that I want to put in front of humanitarian logisticians specifically because the operational implications are immediate.

The conventional read of the 2026 oil shock is that it is a 2022 repeat with higher prices. That read is wrong, and the reason it is wrong is jet fuel.

Twenty-one per cent of the world's seaborne jet fuel supply has been cut off at source. That is the figure from maritime intelligence firm Kpler, reported by the aviation publication The Air Current on 6 April. Kuwait alone, the world's second-largest jet fuel exporter, accounted for 15 per cent of global seaborne supply in 2025, and Kuwait announced production and refining cuts on 7 March. More than three million barrels per day of Middle East refining capacity is damaged or shut. Saudi Arabia's Ras Tanura refinery has stopped fuel production. Bahrain's Al-Ma'ameer refinery is damaged. The UAE's Ruwais refinery is offline while drone damage is assessed. This is physical reconstruction territory, not market clearing.

Here is the part that the conventional read misses. The obvious substitute supply, which would be either US shale or Asian refineries running harder, cannot fill the gap. US shale is the wrong kind of crude oil to make jet fuel efficiently. It is light and sweet, which is the chemical opposite of the medium-to-heavy sour Gulf grades that Middle East refineries were configured to process for middle distillates. You cannot turn light sweet shale into Arabian Medium jet fuel yields by flipping a switch.

One important caveat. Jet fuel yield depends not only on the crude being processed but also on the specific configuration of the refinery processing it. Complex US Gulf Coast refineries with hydrocrackers and cokers can run heavier slates than the typical US refinery, and a significant portion of that complex capacity was configured over decades to run imported heavy sour crude from the Middle East, Venezuela and Mexico. The mismatch argument therefore depends on the right crude reaching the right refinery, not on crude alone. But the point still holds: the heavy sour feedstock those refineries were built for is now stuck behind Hormuz.

The cleanest empirical proof is in the trade data. The United States is the largest supplier of refined petroleum products to Europe overall, but only the seventh-largest supplier of jet fuel specifically, accounting for just 3 per cent of European jet fuel inflows. That gap is the molecular mismatch showing up directly in the trade data. If you remember one fact from this piece, remember that one.

Asian refiners cannot fill the gap either. China has asked its firms to suspend new refined fuel export contracts. Thailand has halted oil exports. South Korea imposed a mandatory export cap from 17 March. Japan has cut refinery runs by 10 per cent. A Singapore refinery is running at 60 per cent of capacity. The substitution pathway does not exist within the relevant timeframe.

Now here is where it lands for humanitarian operations.

The jet fuel currently being pumped into aircraft at European and Asian airports left the Middle East before the war began on 28 February. The global pipeline of in-transit tankers and airport fuel farm buffers is approximately six to eight weeks deep on average, with significant variation by location. The defensible prediction is that the second half of April 2026 is when physical jet fuel shortage starts reaching the wing at the tightest European hub airports, with Asia-Pacific lagging by one to three weeks. The signal to watch for is flight cancellations driven by capacity-managed fuel allocation rather than ordinary schedule optimisation.

That is this week and next week. Not Q3. Not "later in 2026." This week.

For humanitarian logisticians the implications run in three directions. One, commercial passenger aviation carries the belly freight that moves humanitarian cargo on the major Asia-Europe and Europe-Africa corridors. When airlines cut passenger flights to manage fuel allocation, belly freight capacity contracts in parallel. The capacity reduction is not 1:1 with the passenger reduction because cargo configurations differ, but it is substantial. Two, the cost of moving a humanitarian shipment by air freight in the second half of April and through May is going to be materially higher than the rates that current procurement frameworks were built around. Procurement teams that have not already locked in capacity at pre-shock rates are going to find themselves negotiating into a tightening market. Three, the surge logistics capacity that the global humanitarian system depends on for sudden-onset emergencies, the ability to move staff, medical supplies, and shelter materials from Nairobi, Dubai, Brindisi, Geneva, or Copenhagen to wherever the next crisis breaks, is going to be more expensive and less reliable than it was in March.

This compounds the Mercy Corps paper's findings rather than competing with them. The Mercy Corps paper documents what has already landed on the people the system serves. The jet fuel finding is about what is about to make the system itself less able to respond. Both are true. Both need to be in the planning conversation this week.

What you should be doing this week

If you are running cash programming in any of the five Mercy Corps case countries, you should be reading the report and pushing your cash working group to recalculate the MEB against the post-war cost base before mid-May.

If you are running food security programming in Somalia, Ethiopia or Pakistan, you should be tracking retail urea prices against global benchmarks weekly for the next six weeks. The pass-through window is open right now.

If you are running humanitarian logistics through Gulf hubs, you should be modelling continued elevated routing costs through the remainder of 2026 and looking at whether your contingency capacity at alternative hubs (Nairobi, Brindisi, Dakar, Mombasa) is real or theoretical.

If you are running anything that depends on commercial aviation belly freight, you should be having a conversation with your procurement team this week about what your air freight rate exposure looks like through May, because the second-half-of-April jet fuel buffer is about to start binding and the rates you negotiated in February are not going to be the rates you pay in May.

And if you are in a donor capital, the energy shock is about to make every existing humanitarian funding gap worse. Yemen at $51 per person in need for the year. Ethiopia at $41. The DRC at $35. Those numbers were already inadequate. They are about to buy materially less.

A month ago I made a call. Six weeks later, most of it has landed, in a few places it has gone further than I expected, and in one place I should have been more precise about why. The strait is still not commercially open. The harvest threshold has been crossed. Transfer values need revising before mid-May. The jet fuel buffer is about to run out. The people the system is supposed to serve are paying war-era prices and will continue to pay them long after the headlines move on.

None of this is hypothetical anymore. The window for the decisions that matter is this week and next, not Q3.

The next newsletter will go deeper on the cash and voucher assistance implications, where the operational urgency is highest right now. If you are running CVA programming in any of the affected countries, I want to hear from you. What is breaking. What is holding. What your transfer values look like against this week's prices. The remittance call from March is also still open and I am still tracking it. If anyone has visibility on Gulf labour markets or remittance flows since late February, please get in touch.

Read The Long Reach of War here: https://www.mercycorps.org/sites/default/files/2026-04/the-long-reach-of-war.pdf

Tom