The US-Israel war with Iran began on February 28. By March 20 — three weeks later — the UK's government borrowing rate had climbed above 5% for the first time since the 2008 financial crisis. UK household energy bills are forecast to rise by £332 per year in July. And economists say the government has less fiscal room to cushion the blow than it did during the last energy shock.

This is what energy wars cost economies that didn't fight them.


The UK Borrowing Numbers

5%+
UK 10-year government bond yield — 18-year high
£14.3B
UK government borrowing in February 2026 — 2nd highest on record for that month
93.1%
UK national debt as % of GDP — levels last seen in the early 1960s
£1 in £10
Of every pound the UK spends, this goes to debt interest
Sources: Office for National Statistics, BBC News (March 20–21, 2026)

February borrowing came in at £14.3 billion — £2.2 billion higher than the same month last year, and far above the £8.8 billion economists had forecast. The Office for National Statistics attributed the overshoot to higher spending, debt interest payments, and timing of scheduled payments.

The 10-year gilt yield — the benchmark for UK long-term government borrowing costs — crossing 5% is significant. It means the government pays more to service its existing debt and more for any new borrowing. At 93.1% of GDP, UK debt is already at levels not seen since the early 1960s.

"The government doesn't have the room for manoeuvrability it had in 2022 after the energy price shock following Russia's invasion of Ukraine."
— Charlie Bean, former Deputy Governor, Bank of England

Household Energy Bills: The July Forecast

Energy consultancy Cornwall Insight forecasts that typical UK household energy bills will rise by £332 per year in July — from the current cap of £1,641 to £1,973 annually. The driver is the surge in wholesale oil and gas prices following the Iran war.

The Ofgem energy price cap — which sets the maximum per-unit charge for gas and electricity — is reset every three months. The July cap will be based on wholesale prices in March, April, and May. With three weeks of Iran war energy pricing already in the March data, the trajectory is upward.

£1,641
Current annual energy cap (typical household)
£1,973
Forecast July cap — Cornwall Insight estimate
+£332
Projected annual increase from July
£35B+
Cost of 2022 universal energy support package (Russia-Ukraine shock)
Sources: Cornwall Insight, Ofgem, BBC News (March 2026)

Cornwall Insight notes the forecast could move significantly — either higher or lower — depending on where wholesale prices land through May. A further escalation in the Iran conflict would push prices higher. A ceasefire or diplomatic breakthrough could pull them back.


Why 2026 Is Different from 2022

When Russia invaded Ukraine in February 2022, the UK's energy bills surged similarly. The government responded with a package that applied to every household — universal bill support that ultimately cost more than £35 billion. It was expensive but politically straightforward: the shock was severe, the political pressure was intense, and the government's fiscal position allowed it.

That position no longer exists in the same form.

Ruth Gregory, deputy chief UK economist at Capital Economics, said: "We doubt there is scope for a large-scale fiscal support package like that seen in 2022, even in more extreme scenarios in which the conflict in the Middle East escalates further."

Chancellor Rachel Reeves has signaled that any support would be targeted — directed at vulnerable and lower-income households — rather than universal. That approach costs less but reaches fewer people.


The Global Pattern

The UK is not alone. The mechanism is consistent across oil-importing economies: energy prices rise, inflation expectations rise, central banks face pressure to maintain or raise rates, government borrowing costs increase, fiscal space narrows. The 2022 Russia-Ukraine shock demonstrated this pattern across Europe, the UK, and the United States.

The 2026 Iran war shock is following the same track. The US has insulated itself somewhat — it is a net energy exporter and not directly dependent on Middle Eastern oil volumes. But as noted in Ranked's earlier Jones Act piece, global oil markets are integrated: a price spike anywhere lifts prices everywhere, including US pump prices.

The UK, which imports a significant share of its energy, absorbs the shock more directly. So does Japan, South Korea, most of Europe, and the developing world. The economic effects of a war the UK had no vote on are arriving in British household energy bills and government bond markets simultaneously.

In 2022, the government provided £35B in universal energy support after the Russia-Ukraine shock. Economists say it cannot afford a comparable response to the Iran war shock. The fiscal cushion is gone.

What Comes Next

The Ofgem July cap will be set on May 27, based on wholesale prices through May. If the Iran conflict remains unresolved, energy prices will remain elevated through that period, locking in the higher cap.

Political pressure on the UK government to act is growing. The debate between universal and targeted support is genuinely difficult: universal is simpler and provides more certainty to households, but costs more at a time when the government has less to spend. Targeted is cheaper but requires means-testing infrastructure that takes time to implement.

The war that "doesn't affect" the US because it's an energy exporter is landing on British household energy bills in July. The fiscal math says the government will struggle to fully absorb it.

Ofgem sets the cap May 27. Mark that date.