American consumer prices surged to a three-year high in May, the headline annual rate vaulting to 4.2 per cent — a full two percentage points above the Federal Reserve’s target — as the closure of the Strait of Hormuz in the Iran conflict sent energy costs spiralling. The increase, up from 3.8 per cent in April and just 2.4 per cent in February before the war began, marks the third consecutive monthly acceleration and the first breach of the 4 per cent mark since early 2023. The energy index alone accounted for more than 60 per cent of the monthly rise, with gasoline prices up 7 per cent from the previous month and more than 50 per cent since the US-Israel bombing campaign commenced on 28 February. Yet beneath the fuel-driven headline shock, core inflation — excluding food and energy — edged up a more restrained 2.9 per cent year-on-year, offering a sliver of comfort that demand-side pressures remain, for now, contained.

The political and monetary-policy reverberations are immediate. With real average earnings falling 0.7 per cent over the year and inflation outpacing wage growth for a second straight month, the pocketbook pain is intensifying just as voters prepare for November’s midterm elections. Viewed from Washington, the White House insists the price shock will be temporary and that a peace deal is imminent, but the data hand Kevin Warsh — presiding over his first meeting as Fed chair — little room to manoeuvre: expectations have rapidly shifted from rate cuts to a prolonged hold through 2027, and some traders are even pricing a risk of hikes. In London, analysts note that while the core reading remains moderate, it has not fallen, and any further energy pass-through to services or goods would fundamentally alter the inflation narrative.

Looking at the same numbers from other capitals, a more fragmented picture emerges. In Moscow, economic observers highlight the supply-side nature of the shock — driven not by American overheating but by a physical blockade of a fifth of global oil transit — and point to falling prices for transport services, new cars and medical insurance as evidence that domestic demand is already cooling. From Beijing, where policymakers worry about global trade contagion, the focus falls on the Strait of Hormuz’s continued closure as a structural brake on world growth. In continental Europe, there is unease that a sustained spike in US import costs could ripple through dollar-denominated supply chains, even as European inflation itself has been more muted.

Forward-looking analysis remains tethered to geopolitics. Stock markets fell on Wednesday, dragged down not merely by the inflation print but by a tech sell-off and the absence of any diplomatic breakthrough between Washington and Tehran. If oil prices stay elevated, the energy shock will increasingly embed itself in production costs, shipping and ultimately consumer expectations, pulling core inflation higher and extinguishing any residual hope of monetary easing this cycle. For the Trump administration, the clock is ticking: every week that the Strait remains shut compounds the cost-of-living squeeze, turning the midterms into a referendum on the economic management of a war whose duration and exit strategy remain opaque.