How the War in Iran Is Rerouting Hundreds of International Flights and Adding Billions to Operating Costs

The departures board at Heathrow on a recent Tuesday afternoon told a story that ticket prices alone couldn’t. Flights to Singapore delayed. A Hong Kong service rerouted through a longer southern corridor. Passengers staring up, recalculating connections, some still thumbing through booking apps as if a refresh might undo the last six weeks. Airline staff, when asked, gave the kind of practiced shrug that suggests they’ve answered the same question fifty times that morning.

The war that began on February 28 has done something the pandemic, oil shocks, and even 9/11 took longer to do. It has quietly redrawn the map of global aviation in roughly eight weeks. Air fares are up nearly a quarter on average compared with last year, according to the consultancy Teneo, and that headline number hides much sharper pain on specific routes. London to Melbourne in June now costs 76% more than it did last summer. Hong Kong to London, 72%. These aren’t theoretical figures. They’re showing up on the screens of people trying to visit family, attend conferences, get home.

Behind the numbers sits a less visible mechanic. Airspace over Iran and parts of the Gulf has been effectively closed to most carriers, forcing flights to swing south through the Arabian Peninsula or north over the Caspian, adding fuel burn that pilots used to budget for headwinds, not geopolitics. Then there’s the fuel itself. Jet fuel that traded around $85 to $99 a barrel at the start of the year has spiked to as high as $209. Fuel already accounts for up to a quarter of an airline’s operating costs. Do the arithmetic and the surcharges showing up at checkout start to feel almost restrained.

There’s a sense, talking to industry analysts, that carriers are operating with one eye on the war and one on the calendar. Summer is approaching. Schedules are locked months in advance. Air Canada has pulled its New York JFK service from June through late October to conserve fuel. United, Delta, Air France-KLM, SAS, Cathay Pacific, Philippine Airlines — each has trimmed routes or signaled price hikes if Iran’s blockade of the Strait of Hormuz holds. Gulf carriers, normally the workhorses of long-haul connectivity, have lost meaningful capacity. Rivals have stepped in, but only partway. There are simply fewer seats.

Transport & Environment, a Brussels-based campaign group, ran the math on what this means per passenger. About €88, roughly $104, in added fuel cost on long-haul flights leaving Europe. €29 within Europe. A Paris–New York ticket carries €129 more in fuel alone. These numbers are for wholesale. They usually land heavier by the time they get through airline pricing systems.

It’s difficult to ignore how rapidly the industry’s lexicon has changed. Carriers were discussing premium leisure and post-pandemic momentum a few months ago. Executives now use the more archaic terminology of capacity discipline, route economics, and fuel hedges. Atmosphere Research’s Henry Harteveldt has cautioned that it would take months to resume regular jet fuel production and delivery even in the event of a ceasefire. In short, airlines are being cautious because they must be, according to Shye Gilad, a former captain who is currently teaching at Georgetown.

How long passengers will tolerate this before changing their behavior is still unknown. Once a wise traveler’s instinct, the wait-and-see strategy appears riskier as summer approaches. Some people are willing to pay. A few will cancel. Tokyo will be subtly downgraded to Lisbon by some. Watching this unfold, you get the feeling the aviation industry is rehearsing a script it has run before — just with a different war, a different fuel curve, and a different set of hopes about how soon any of it ends.