The Jet Fuel Supply Chain, Explained Before It Breaks

A technical follow-on to The Jet Fuel Cliff, 13 April 2026. This piece develops the supply chain mechanics behind the jet fuel finding in that newsletter and sits alongside The Long Reach of War, the Mercy Corps Crisis Analysis Team flash report published on 13 April, which is the substantive evidence base for the humanitarian transmission analysis. Read the Mercy Corps paper here: The Long Reach of War

The jet fuel buffer at major European airports runs out somewhere between 30 April and 12 May. That window is my synthesis of the ACI Europe "within three weeks" warning from 9 April and the Rystad Energy "three to four weeks" call from 14 April, not either source's stated forecast date. Between two and four weeks from today. Most readers covering the Iran war still think this is a crude oil problem. It is not.

In the 13 April newsletter I argued that the jet fuel buffer would start binding in the second half of April, that humanitarian logisticians needed to be acting this week, and that the capacity reduction at European hubs would cascade into belly freight on the routes humanitarian cargo moves on. A week later, most of that has landed. SAS has cancelled 1,000 flights in April. Ryanair is warning of May and June capacity cuts. ACI Europe has written to the European Commission. The Rystad chief economist has confirmed the three-to-four-week timeline on CNBC. The Strait of Hormuz ceasefire has not reversed the buffer depletion and will not, because the commercial reopening requires insurance and crew confidence that a fragile truce cannot provide.

This piece explains the supply chain mechanics behind the Jet Fuel Cliff finding. Why the shock is structurally different from a crude oil price spike. Why the US cannot substitute. Why the buffer depletion is fixed on a physical timeline that does not respond to political negotiation. Why this is a one-to-three-month problem on the supply side and a four-to-twelve-month problem on the recovery side. It focuses on the April-to-May window because that is when the physical buffer runs out. Physical mitigation pathways exist on a longer horizon and are discussed in a dedicated section below.

A note on what this piece is and is not. It is a desk review of publicly available industry and trade reporting through 16 April, validated through conversations with a former oil and gas sector executive on infrastructure and mitigation pathways, and with a UK-based private pilot on general aviation conditions. It is not an insider account of contingency planning inside Gulf producers, European Commission working groups, or airline operations centres. Where the piece describes mitigation pathways that are not being pursued, or decisions that are not being made, that judgement rests on the absence of public announcement rather than on direct visibility of internal planning. If contingency work is happening behind closed doors that would materially change the four-to-six-week picture, I do not currently see it, and readers with visibility I do not have should push back.

One barrel of crude is not one barrel of jet fuel.

A barrel of crude oil yields a fixed product slate determined by refinery configuration. Kerosene jet fuel accounts for around 9 to 10 per cent of each barrel depending on refinery configuration, according to the IATA 2025 Fuel Fact Sheet. Gasoline takes roughly 45 per cent. Distillates including diesel and heating oil take another 25 per cent. The jet fuel fraction sits in the middle of the barrel, between the lighter products at the top and the heavier products at the bottom.

This matters because refineries cannot arbitrarily reallocate output when jet fuel prices spike. The chemistry of crude distillation is fixed by the feedstock and by the cracker configuration of the specific refinery. A refinery designed to produce a slate heavy on gasoline cannot simply decide to produce twice as much kerosene next week. It can make marginal adjustments, and the current elevated crack spread gives it every incentive to do so, but the upper bound on that reallocation is set by the equipment, not by the market.

Global jet fuel consumption is running at 7.788 million barrels per day in 2025, rising to nearly 7.99 million in 2026. That is roughly 120 billion gallons a year. Jet fuel is a lower priority for refineries than diesel and gasoline. Refinery operators optimise for the higher-demand, higher-margin products. Jet fuel gets what is left after those flows are secured.

Three countries dominate global seaborne jet fuel exports. Two cannot scale. One is locked in.

The world's three largest jet fuel exporters are China, South Korea, and Kuwait. The NPR business desk summarised the current position in a single sentence on 15 April: China and South Korea cannot make enough right now, and Kuwait cannot get it out.

China has suspended new jet fuel export contracts, which is effectively an export ban for the current contracting window, as domestic demand growth has outpaced refinery throughput. South Korea's refineries are operating at high utilisation but have no further capacity to expand output at the speeds required. Kuwait, specifically the world's second-largest jet fuel exporter at 15 per cent of seaborne supply in 2025 per Vortexa, produces at scale and has cargoes ready, but its tankers have to transit the Strait of Hormuz to reach world markets. Kuwait Petroleum Corporation declared force majeure on its crude and refined product exports on 7 March, confirmed by Reuters and Argus. The force majeure is still in place. Kuwaiti jet fuel is sitting in storage or loaded on tankers that cannot exit.

The structural dependence here is what matters. Europe draws approximately 25 to 33 per cent of its jet fuel demand from Gulf supplies, according to ACI Europe. The Financial Times reports that 40 per cent of global seaborne jet fuel transits Hormuz. EU aviation fuel imports from Gulf refineries account for over 60 per cent of total imports, with more than 40 per cent of that volume passing through the chokepoint. ACI Europe noted in its 9 April letter to the EU Commissioner for Sustainable Transport that the United States supplies only 3 per cent of European jet fuel pre-war. The US cannot substitute at scale.

The mismatch is chemical. US shale oil is light sweet, with an API gravity in the 38 to 45 range and very low sulphur content. Gulf crudes sit at 29 to 34 API and above 1.3 per cent sulphur, which is the specification that produces middle distillates, including jet fuel, most efficiently. A refinery optimised for shale produces naphtha and gasoline and structurally less jet fuel.

The validation is in the trade data. Across all refined petroleum products the United States was Europe's largest supplier in 2025. For jet fuel specifically, the US was the seventh-largest, with approximately 16,000 barrels per day of exports to Europe, roughly 3 per cent of European inflows. Largest refined-products supplier overall. Seventh for jet fuel. That is the mismatch showing up in the numbers, not in theory.

How long do we have?

Jet fuel inventories at major airport hubs typically hold around six to eight weeks of operational supply. This is the physical buffer between a supply disruption and operational impact.

That buffer started running down on 28 February. We are now seven weeks in. The ACI Europe letter dated 9 April warned that systemic jet fuel shortages would hit European airports within three weeks if Hormuz did not reopen stably. Rystad Energy's chief economist Claudio Galimberti told CNBC on 14 April that the situation would become systemic within three to four weeks with severe cuts to European flights in May and June. Both timelines land in the same window, which my interpolation places at roughly 30 April to 12 May.

I have been tracking Kuwaiti cargo flows since 28 February through Kpler data and AIS-derived public reporting. The inventory clock does not care about political negotiations. It runs at the same speed whether Hormuz reopens in May or in July.

The IEA's Oil Market Report on 14 April provided the first comprehensive data on what is already happening. Middle East aviation jet and kerosene demand is down 130,000 barrels per day for March to May compared to the same period last year. UAE aviation is operating at around 40 per cent of pre-crisis levels based on AirNav Radar data. Qatar is at 25 per cent. Iran, Iraq, and Kuwait have almost no recorded commercial flights since the start of the conflict. Saudi Arabia is holding at 80 to 90 per cent but under increasing pressure.

These are not future scenarios. They are operational realities as of mid-April, across both aviation and road fuel markets, which matter to humanitarian operations in different ways.

On aviation specifically. Italy has introduced formal jet fuel rationing at seven airports. Myanmar has suspended all major domestic airlines. Vietnam has cut 23 domestic flights per week. A UK-based private pilot I spoke with this week reports that FBO jet fuel prices at small airfields are tracking the Aviation Research Group's April survey number of $8.63 per gallon, up $1.77 on March. That is one pilot's report from one set of UK airfields rather than a documented sector-wide pattern, and worth flagging as an emerging signal to watch.

On road fuel, which matters to humanitarian operations through in-country logistics and programme transport rather than through aviation. Ireland has over 600 petrol stations dry alongside the Whitegate refinery blockade. Slovenia has introduced the EU's first formal road fuel rationing cap at 50 litres per day. These road fuel disruptions sit one step removed from the jet fuel cliff that is the focus of this piece, but they are part of the same underlying shock and will affect the same humanitarian operations from a different direction.

Prices have already doubled. Crack spreads have exploded.

The IATA Jet Fuel Price Monitor recorded a global average price of $197.83 per barrel last week, down 5.3 per cent from the week before but still at crisis levels. In the US, Jet-A rose from $2.50 per gallon on 27 February to $4.88 per gallon by 3 April, a 95 per cent increase in five weeks.

The most important number for understanding future airline economics is the crack spread. This is the difference between the crude oil price and the refined jet fuel price. It represents the refiner's margin for converting crude into kerosene.

In a normal market, the jet fuel crack spread runs at $10 to $25 per barrel. The Argus US Jet Fuel Index is currently showing crack spreads in the range of $65 to $138 per barrel. That is three to seven times the normal range. It is a textbook signal of refining capacity failing to keep pace with demand.

Crack spreads at these levels tell us something the spot price alone does not. Even if Brent crude stabilises or falls, the jet fuel price can stay elevated because the bottleneck is not in crude supply. It is in refining capacity and molecular slate.

Airlines are largely unhedged. The financial shock is real and concentrated.

One structural factor has amplified the shock for airlines. No major US carrier maintains a traditional financial hedging programme. The industry exited hedging during the low-volatility environment of 2024 and 2025, convinced that the hedging premiums were not worth the protection. That decision is now costing the US airline industry an estimated $25 billion in unbudgeted fuel expense for 2026 according to industry reporting.

The exception is Delta, which owns the Monroe Energy refinery in Pennsylvania as a natural hedge against crack spread movements. Delta has maintained its 2026 earnings guidance of $6.50 to $7.50 per share through the shock. American Airlines, unhedged, has seen UBS cut its 2026 earnings estimate from over $2.00 per share to $0.43. The Delta-American contrast is the clearest illustration I have seen of what unhedged exposure means when the shock actually arrives.

The implications for airline capacity are playing out in public. SAS announced 1,000 April flight cancellations in company communications reported by CNBC on 10 April. Ryanair CEO Michael O'Leary warned on the same CNBC report that 10 to 25 per cent of European supplies are at risk in May and June and that Ryanair will cut capacity if the shortage continues. Wizz Air's €50 million hit to 2026 net profit was disclosed in March earnings guidance. Virgin Atlantic's CEO Corneel Koster told the Financial Times on 14 April that the airline will struggle to turn a profit this year even with fuel surcharges applied. United has announced a 5 per cent capacity reduction. Cathay Pacific has cut schedules. Ten days ago this was prediction. Today it is announced corporate strategy at every major carrier with exposure to the Gulf supply chain.

The second-order transmission few are tracking.

The humanitarian sector has begun to pay attention to jet fuel because of flight disruption. That misses where the damage will actually concentrate.

Passenger aircraft carry around half of all international air freight in their belly hold. When airlines cut capacity, freight capacity is cut alongside passenger capacity. Special cargo, which means pharmaceuticals, high-tech components, perishables, and dangerous goods, accounts for around 21 per cent of global airfreight volumes and moves at yields 1.5 to 2.5 times higher than general cargo. This is the cold chain economy, the just-in-time pharmaceutical economy, and the humanitarian supply economy.

Pharmaceutical air cargo demand is rising faster than any other segment in the 2026 forecast. Healthcare companies are already seeing the squeeze. Temperature-controlled shipments are being prioritised onto the capacity that remains, which means baseline freight rates are rising for everyone else. IRC reported this month that over 600 boxes of therapeutic food destined for severely malnourished children in Somalia remain stuck in India because of freight disruption. UNICEF confirmed $15.7 million in lifesaving supplies hanging in transit to Somalia. The UNICEF Executive Director's statement of 26 March directly linked Middle East war fuel and supply disruption to Somali child malnutrition.

One honest caveat on the causal attribution. Jet fuel shortage is a contributing factor to air freight disruption, but it is not the only factor, and the current public data does not allow clean isolation of the jet fuel contribution from other freight constraints. The mechanism linking jet fuel price and availability to belly cargo capacity is clear. The magnitude of the jet fuel share of the total freight disruption is inferred rather than directly documented. An ECHO desk reviewer applying EMMA-style evidence grading to the Somalia therapeutic food example would mark it as single-source reported, causally plausible, magnitude unverified.

The air cargo transmission channel will hit three humanitarian priorities in sequence. First, vaccine cold chain reliability for routine immunisation programmes that depend on time-sensitive belly cargo from Europe to Africa. Second, therapeutic food and nutrition supply pipelines that have already been disrupted, and which The Long Reach of War documents in country-specific detail for Somalia and Ethiopia. Third, medical commodity supply for major health emergencies where the fast replenishment cycles are built on commercial air freight capacity that is now being withdrawn.

What could change the picture.

The buffer depletion maths is correct for April and May. Physical mitigations exist that would change the picture over a six to eighteen month horizon. Any serious analysis of this shock has to reckon with them, because the mitigation pathway is what separates a temporary shock from a structural one.

The specific mitigations are well known to the oil and gas sector. Saudi Arabia's East-West pipeline runs roughly 1,200 km from the Eastern Province to Yanbu on the Red Sea, with a nameplate capacity of around 5 million barrels per day of crude, expandable toward 7 million. The Habshan-Fujairah pipeline in the UAE bypasses Hormuz to the Gulf of Oman at around 1.5 million barrels per day. Both could run harder than they currently do. Expansion of jet fuel storage capacity at major hubs is straightforward infrastructure that can be built in months rather than years. Emergency refinery reconfiguration toward middle distillates is politically and commercially awkward but technically achievable at the world's more complex refineries.

A former oil and gas sector executive who worked on the Baku-Tbilisi-Ceyhan pipeline pointed out to me this week that roughly 80 per cent of global seaborne jet fuel output is not directly affected by Hormuz, and that the distribution fragility of the remaining share is addressable with infrastructure that is quick to construct relative to how the problem is currently being framed. That 80 per cent figure aligns with Kpler's estimate that 21 per cent of global seaborne jet fuel supply has been cut off at source. The 80 per cent and 21 per cent figures measure slightly different things, seaborne output versus seaborne supply, but they are directionally consistent. His point stands. The engineering is not the binding constraint. From the outside, the binding constraints appear to be political will, capital commitment, and the willingness of governments to treat this as a 1970s-scale emergency requiring 1970s-scale policy responses. Readers with direct visibility of those decisions may characterise the constraints differently. On publicly available evidence, those commitments are not visible. I do not have insider visibility of Gulf state, European Commission, or IATA internal planning, and readers who do should correct the record if contingency work is underway that has not yet been announced.

The political economy question humanitarian readers should be asking is who could act. Gulf states have the pipeline throughput decisions on Saudi East-West and Habshan-Fujairah to make. The European Commission has the storage capacity investment and strategic reserve decisions, which ACI Europe has already formally requested in its 9 April letter. National aviation regulators and IATA have the demand-side levers, including airline capacity coordination and non-essential flight restrictions, that were used in previous fuel crises and have not yet been put on the table in this one. Humanitarian sector leadership with relationships in any of those capitals has a specific advocacy handle available this week. The pathway is known. The public decisions have not yet been made. If the private decisions are further along than the public record suggests, the humanitarian sector benefits from knowing, and readers in any of those capitals should get in touch.

There is also a seasonality note worth adding. Northern hemisphere heating demand eases from April to September, which softens the pressure on distillates used for home heating. Aviation demand runs the opposite way. European summer travel peaks between June and August, which is the worst possible timing for a jet fuel shock. The seasonality argument that applies to heating oil cuts the wrong direction for jet fuel.

The current ceasefire picture.

A fragile partial reopening has been underway since 12 April, when three supertankers exited Hormuz under the current ceasefire. Kpler data cited by CNN on 12 April reports approximately 400 loaded tankers attempting to exit the Gulf, against only around 100 empty tankers willing to enter. Analysts assess full normalisation would take until July even if the ceasefire holds. The US blockade of Iranian ports that began on 13 to 14 April has added a further risk layer for vessels transiting the region. Iran's Revolutionary Guard is reportedly charging up to $2 million per tanker transit, payable in yuan or cryptocurrency. This is not Hormuz reopening. It is partial outbound clearance of the cargoes trapped on 28 February. Loading new cargoes at Kuwaiti, Emirati, and Saudi terminals remains visibly constrained on the public reporting. The buffer depletion maths as I have calculated it is unchanged, though a more complete picture of terminal-level loading activity would improve precision on the April-to-May window.

What to watch.

Six indicators will tell us which direction this moves over the next four to six weeks.

One, the Platts Jet Fuel Price Index published weekly by IATA. A return toward $120 to $140 per barrel would indicate easing. A move above $220 would indicate escalation.

Two, the Argus US Jet Fuel crack spread. A return to $30 to $40 per barrel would indicate refining capacity rebalancing. A move above $150 would indicate the molecular slate problem is hardening.

Three, ACI Europe communications. A follow-up letter or press statement during the first half of May would confirm the three-week warning timeline has materialised.

Four, flight schedule filings from the major European carriers for June and July. SAS, Lufthansa Group, Air France-KLM, Ryanair, and Wizz Air all file schedules with regulators well in advance. Visible schedule contraction in June filings from mid-May onward would confirm structural rather than temporary capacity reduction.

Five, Kuwait Petroleum Corporation force majeure status on refined product exports. KPC declared force majeure on 7 March. A formal lifting of force majeure would indicate Hormuz is reopening at scale. Continued force majeure through May would confirm the choke.

Six, belly cargo capacity indices published by Xeneta and IATA. A decline in belly capacity alongside maintained freighter capacity would signal that passenger capacity cuts are cascading into cargo markets.

What this means for humanitarian operations.

The jet fuel shock is not transitory and is not a crude oil story. It is a structural refinery allocation problem with three specific exporters of which one is physically locked in and two cannot scale. The buffer depletion is already visible and is operating on a timeline that lands inside the next four to six weeks. Physical mitigations exist, but they operate on a six to eighteen month horizon and require political decisions that have not yet been made.

Willie Walsh of IATA has publicly compared the industry recovery trajectory to 9/11, which took around four months, and the 2008 to 2009 financial crisis, which took ten to twelve months. Walsh is the industry's lead advocate for airline relief, not an independent forecaster, and his analogues measure airline passenger recovery rather than jet fuel supply chain normalisation, which may run on a different clock. With those caveats, four to twelve months appears to be the working public baseline for industry recovery, though it rests on a single industry-advocate source. Humanitarian operations should plan against that range while treating it as indicative rather than definitive, and should certainly not be planning against a four-to-six-week horizon.

For humanitarian operations, four specific things follow.

One, identify the commodity exposures. The commodities most directly exposed to the belly freight contraction are vaccines and cold chain pharmaceuticals moving Europe to Africa, therapeutic food moving India to Somalia and the Horn, medical commodities moving on the Europe-to-Africa and Asia-to-Africa corridors, and the surge replenishment stock that the humanitarian system depends on for sudden-onset emergencies. The Long Reach of War documents the therapeutic food and medical commodity exposures in Somalia and Ethiopia with country-specific evidence. Identifying which of your pipelines fall into these categories is the first step.

Two, test the redundancy honestly. Redundancy is the word donors use when they don't know what to recommend. What it actually means here is specific. Is your pipeline single-sourced on Europe-to-Africa belly cargo, or is there a dedicated freighter alternative? If the passenger flights on your corridor are cut in May, what is your fallback routing? Are alternative hubs (Nairobi, Brindisi, Dakar, Mombasa) real operational options or paper contingencies?

If you cannot answer those three questions by end of next week, your redundancy is more theoretical than you would want it to be.

Three, revise programme budgets. Procurement teams that have not already locked in air freight capacity at pre-shock rates are going to be negotiating into a tightening market through May and June. Programme budgets built on February 2026 aviation costs need revising now for Q2 and Q3. Cash working groups in the five countries covered by The Long Reach of War should be recalculating the minimum expenditure basket against the post-war cost base before mid-May, as I argued in the 13 April newsletter.

Four, add the right indicators to monitoring systems. Fuel price data is the lagging indicator most humanitarian analysts already track. Add airline capacity filings, crack spreads, and belly cargo indices as leading indicators. They will move before the fuel price does, and they will tell you what is about to happen to your supply chain before it arrives at your warehouse.

The sector has tended to treat aviation as infrastructure that simply works. For the next six to twelve months, that assumption is unsafe.

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Sources. IATA 2025 Fuel Fact Sheet and Jet Fuel Price Monitor. ACI Europe letter to EU Commissioner for Sustainable Transport and Tourism, 9 April 2026. IEA Oil Market Report, 14 April 2026. Kpler via The Air Current, 6 April 2026. Kpler via CNN Business, 12 April 2026. Vortexa, 9 March 2026. Argus Media, 7 March 2026 (KPC force majeure) and ongoing Jet Fuel Index. Reuters, 7-8 March 2026. Aviation Research Group April 2026 FBO survey. Financial Times, 14 April 2026. CNBC, 10 and 14 April 2026. NPR business desk, 15 April 2026. Rystad Energy commentary, 14 April 2026. CNN Business, 9 and 12 April 2026. Al Jazeera, 12 and 14 April 2026. UNICEF Executive Director statement, 26 March 2026. Mercy Corps Crisis Analysis Team, The Long Reach of War: The Middle East Conflict's Economic Impact on Fragile Contexts, 13 April 2026. MarketImpact, The Stagflationary Signature, 12 April 2026, and The Jet Fuel Cliff, 13 April 2026.

Acknowledgements. This piece has benefited from conversations with a former oil and gas sector executive who worked on construction of the Baku-Tbilisi-Ceyhan pipeline, and with a UK-based private pilot, both of whom provided technical and operational context on infrastructure and general aviation fuel conditions respectively. The humanitarian transmission analysis builds on the evidence base in The Long Reach of War, authored by Holly Topham and the Mercy Corps Crisis Analysis Team, to which I contributed during the drafting week. Neither the sources above nor the Mercy Corps team are responsible for any errors of interpretation, which remain mine.

What I want to hear from you. If you are running humanitarian logistics through Gulf hubs or relying on Europe-to-Africa belly freight, what does your air freight rate exposure look like through May? What are you seeing on procurement quotes this week versus two weeks ago? WhatsApp me, email me, share in the comments. The sector needs real-time ground truth. The next piece will go deeper on the cash and voucher assistance implications, where operational urgency is highest right now.