Iran War: How Close is the UK to Flight Cancellations?

Pressure on global supply chains is intensifying as the conflict involving Iran shows little sign of easing, with aviation emerging as one of the most exposed sectors.

UK flights are not yet being cancelled at scale, but the risk window is narrowing. An increasing number of industry experts are warning that if disruption to jet fuel supply persists into the early summer months, airlines may soon be forced to cut capacity.

The UK appears closer to that tipping point than any other major aviation market in Europe. A combination of import dependence, supplier concentration and exposure to key global chokepoints has left its jet fuel supply chain particularly fragile.

At the heart of the issue is a structural imbalance. The UK depends heavily on imported jet fuel, with around a quarter sourced from Kuwait. This concentration leaves it more exposed than its European peers to external shocks, particularly those linked to the Middle East.

That vulnerability is amplified by reliance on the Strait of Hormuz, a critical global chokepoint through which more than a fifth of oil supply typically passes. Disruption here is not just a question of reduced output, but of delayed and uncertain delivery, creating friction across the entire supply chain.

For airlines, the issue is increasingly one of access rather than cost. Ryanair has hedged the majority of its fuel costs into next year, insulating it from immediate price volatility. However, the greater concern is whether fuel will be physically available during peak summer months.

UK's reliance on Kuwait

Michael O’Leary, CEO of Ryanair, has warned that even a relatively modest disruption, affecting 10% to 20% of supply, could force airlines to reduce capacity. He is quoted by the Guardian as saying: “Nobody is willing to give us any assurances into June or July. But if there’s a risk to 10% or 20% of the fuel supply in June, July or August, then we and all other airlines would have to start looking at cancelling some flights or taking some capacity out.”

He also highlights the UK’s structural exposure: “Of all the European countries at the moment, the one that is most vulnerable is the UK because of the market share that the Kuwaitis have here. There could be a surplus of jet A-1 fuel in the Middle East, but you have still got to ship it to Europe and we don’t know when or how that happens.”

Signs of how supply stress translates into operational constraints are emerging in Europe. In Italy, authorities introduced temporary fuel controls at key airports including Bologna Airport, Milan Linate Airport, Treviso Airport and Venice Marco Polo Airport. These measures prioritise essential and long-haul flights, while imposing strict limits on fuel for other services. Scandinavian Airlines (SAS) has also cancelled more than 100 flights across Norway.

Such interventions highlight how quickly supply constraints can move beyond pricing pressures and begin to affect operations. Analysts warn that if disruption persists, similar measures could be adopted more widely across the region.

Fuel shortages in Europe and the US

Cristina Haus, Editor of Jet Fuel Intelligence, predicts the effects will soon be felt on both sides of the Atlantic. Speaking in a LinkedIn discussion, she says: “I would say this will start to bite in the next month or so. And it’s not just in Europe.

“Trump this week said we (the US) have a lot of fuel and the Europeans can take it from us. But if you look at the West Coast, where in the last six months two refineries have shut down, California depends on imports from South Korea - one country - for 68% of its supply.

“South Korea has cut its fuel exports and maybe even will stop its exports, so you’re talking about airports in California, Hawaii and the north-west running out of fuel.”

Cristina raises the prospect of fuel rationing, at least in the UK. She says: “Rationing is in the works - it’s a possibility.”

Market signals reinforce the scale of the challenge. Brent crude has climbed above $140 per barrel, reaching levels not seen since 2008 and surpassing those recorded during the Russian invasion of Ukraine, according to S&P Global.

Widespread flight cancellations

At the same time, efforts to stabilise flows remain constrained, with the United Nations lacking a clear legal route to reopen the strait during the conflict.

Operators such as SAVE Group have sought to reassure markets that supply remains sufficient for now, pointing to the presence of multiple fuel providers. However, the broader trajectory points to tightening availability rather than relief.

The result is a growing gap between supply certainty and operational demand across Europe’s aviation sector. For the UK, that gap is wider due to its reliance on imports and limited short-term flexibility in sourcing.

If disruption to fuel flows continues into the summer, the question may shift from when UK flights could start being cancelled to how widespread those cancellations become.