Fresh strikes between the United States and Iran over the weekend have punctured what little calm had settled over the Strait of Hormuz since June’s ceasefire, and nowhere is the anxiety sharper than in Europe’s aviation sector, where fuel reserves are already stretched close to their thinnest point of the year.
The renewed hostilities are less a fresh shock than a relapse. Since the US and Israel launched strikes on Iran at the end of February, the Strait – the corridor that once carried roughly a fifth of the world’s seaborne oil and gas – has swung between closure, partial reopening, and renewed disruption several times over.
A memorandum of understanding (MoU) signed by US President Donald Trump and Iranian President Masoud Pezeshkian in mid-June was meant to end the war and the blockade, but, within days.
Iran said it had closed the Strait again, blaming continued Israeli strikes in Lebanon, a claim the Washington denied. Tanker traffic did partially recover by late June after the US Navy widened a route near Oman, but the reprieve was brief.
The latest flare-up is the most serious yet. On July 7, two tankers – the Qatari-flagged LNG carrier Al Rekayat and the Saudi-flagged supertanker Wedyan – were struck by projectiles inside the Strait, with Al Rekayat evacuated after an engine-room fire. A third vessel was hit within a day, prompting Washington to reimpose sanctions on Iranian oil exports, and launch a new round of strikes on Iranian military sites.
Early on July 12, Iran’s Revolutionary Guard Navy declared the strait closed after saying it had fired warning shots at a ship using an unauthorised route.
By July 13, Brent crude had jumped more than 4% as the two sides traded fresh attacks, touching its highest level since June 22, with US Central Command saying it had struck dozens of Iranian targets overnight, and Iran retaliating with missile and drone strikes on the UAE, Qatar, Kuwait, Oman and Bahrain.
Shipping data underline how thin the traffic has become: Only six vessels crossed the strait in a 12-hour window last Thursday (July 9) and Friday (July 10), against 18 to 22 daily crossings earlier in the month.
Why Europe, specifically, is exposed
The physical geography of the crisis matters less than the industrial geography behind it. Decades of refinery consolidation across Britain, France and Germany left the continent unusually reliant on imported jet fuel rather than domestic refining capacity, and the Gulf had historically supplied around half of that need.
When the war first disrupted flows in the spring, analysts initially expected African economies – almost entirely dependent on Middle Eastern jet fuel – to suffer worst. Instead, Europe has become the more structurally exposed market by mid-summer, even as it has scrambled successfully to plug the gap.
That scramble has been real. Refiners in Italy lifted jet fuel output by around 10% in the first four months of the year, with Eni, which controls roughly half the country’s refining capacity, importing semi-finished feedstock from outside Europe to keep output rising, according to industry sources.
Cargoes have arrived from unfamiliar directions too: Canada, South Korea and India have all stepped in alongside the United States and Nigeria, with Kuwaiti barrels due back on the market in August for the first time since early March. The result was that European jet fuel imports hit 673,000 barrels per day in June, their highest level since October 2025.
Yet, the buffer this has bought is measured in days, not months. Energy Aspects data from mid-June already pointed to a European supply deficit of close to 600,000 barrels a day for the third quarter – a stark contrast with projected surpluses in both the US and Asia-Pacific.
Inventories of 38 million barrels at the start of June compare with roughly 99 million held in the United States, leaving Europe with under 30 days of demand cover by some estimates – the tightest cushion of any major jet fuel market, even after accounting for higher year-on-year stock levels reported by the IEA.
The view from Brussels – and the airlines
European officials have tried to project calm without denying the underlying strain. EU Transport Commissioner Apostolos Tzitzikostas insisted in the spring that there was no evidence of “actual shortages,” even as the bloc weighed importing more jet fuel from the US and considered new minimum reserve quotas.
More recently, EU Energy Commissioner Dan Jorgensen has acknowledged that stocks are likely to tighten further as the summer holiday season peaks, and that Brussels stands ready to coordinate releases from national reserves if the situation deteriorates. That warning looks more urgent now than it did a month ago, given the weekend’s escalation.
Airlines have already adjusted. Lufthansa cut roughly 20,000 short-haul flights through October earlier this year as fuel costs bit into margins, part of a broader pattern of European carriers trimming schedules to conserve fuel rather than let costs spiral unchecked.
Fuel typically accounts for a fifth to a quarter of airline’s operating costs, which is why price swings translate quickly into capacity decisions rather than simply being absorbed. Jet fuel prices in northwest Europe had eased to around USD 133 a barrel from a record above USD 215 at the end of March, a genuine improvement, but the latest exchange of strikes threatens to reverse that trend just as summer travel demand peaks.
What happens next hinges on days, not weeks
Rystad Energy’s Janiv Shah has flagged continued tightness through August as the base case even without further escalation. The renewed fighting makes that base case look optimistic. Brent’s climb toward USD 79 a barrel on July 13, against USD 74 for US crude, reflects markets pricing in a real chance that the June MoU does not hold.
Bloomberg reported Iran declaring the Strait closed “until further notice,” a claim US Central Command disputed, arguing its own strikes were aimed at preserving freedom of navigation rather than restricting it – a dispute that itself signals how fragile the informal arrangements underpinning tanker traffic have become.
For European travellers, the practical upshot for now is less about outright shortages than about capacity and cost: Fewer seats, thinner schedules and airfares that are unlikely to fall even as crude eases from its spring peaks, because demand for the reduced number of available seats remains strong.
Whether that holds through the rest of the summer depends on something no analyst can model with confidence – whether Washington and Tehran can re-establish even the fragile truce that briefly reopened the Strait in June, or whether the current exchange of strikes marks the start of a more sustained third phase of the conflict.