Whitehall protects every energy customer in Britain except the ones who heat with oil. About a million and a half people live that way, and the vast majority of them live where the mains gas network never arrived — the villages off the A-roads, the farms behind the hedgerows, the hamlets the bus passes twice a day.

My husband’s cousin Hannah lives in one of those houses: a stone cottage in Monmouthshire, a two-year-old, a six-month-old, and a 500-litre tank in the garden. Heating oil now runs 111 pence a litre, up from around 60 before the war in Iran began in March. It peaked at 134 in March, eased, and is climbing again as the weather turns. Filling her tank costs about £550. Last winter the same fill cost about £300. That is a £250 swing, every time the gauge drops below a quarter, on a fuel a house with a baby cannot choose not to buy.

I write this from a rowhouse in Philadelphia that sits on a gas line, and that is worth saying plainly: I have a four-year-old and a one-year-old, and my winter crisis is a gas bill, not a tank. This is my family’s problem, not my household’s. The arithmetic, though, is the same arithmetic, and I recognise it — the number at the bottom of the invoice that does not move, and the rest of the month that has to.

This is not a market failure. It is a market working as designed, for everyone except the customers the design left out. Gas and electricity in Britain sit inside a regulatory perimeter: a price cap, an Ofgem licence, a supplier of last resort, a tariff you can challenge. Heating oil sits outside all of it. No cap. No oversight. No backstop. The wholesale disruption — traced by the BBC to the war in Iran and the continuing squeeze on refining — reaches the kerbside tanker in Monmouthshire in real time, the household absorbs it in real time, and nobody in Whitehall has a lever to pull. No government has closed that gap. Every budget since has left it open.

Kacey Musgraves keeps asking the question I now hear in every one of these households: “Am I shapeable clay, or is this as good as it gets?” That is the question a family asks when it cannot tell whether the precarity it is living inside was imposed on it or is simply the shape of the world. For a million and a half people the answer is that it was imposed — by people who drew the map of the energy system and left these houses off it.

Here is the generational stake, and it is not abstract. Three fills across a cold winter — and a cold one takes three — is £750 in extra cost, from a wage that has a competing claim on it. In England the free-hours childcare entitlement does not touch a child under two, so the baby’s nursery place is full price while the tank is full price, and neither is optional. A heat pump would take the household off oil for good, except that the off-grid stock is precisely the stone-walled, rarely insulated housing where heat pumps perform worst and installs run dearest. So the family is not choosing between a heat pump and a nursery place. It is being handed that choice while someone else funds neither.

That is the betrayal in plain terms. The generation that bought the village house and ran it could afford the fuel that keeps it standing. The generation raising children inside those same walls is being priced out of it, one fill at a time, and told the answer is a grant for a decade from now. Diesel has climbed with the crude, refining capacity has been tightening since the autumn, and Cornwall Insight expects the regulated energy cap to rise 16% — so the household that heats with oil also drives to work on the same barrel, and the household on the gas grid is queuing up for the same story in a different form.

The spillover reaches everything else the village buys: the van operator who put his rates up, the volunteer kitchen delivering hot meals across a district with no bus service, the home-care service whose 55p-a-mile reimbursement no longer covers the diesel. And the retired homeowner in Minety, north Wiltshire, who told the BBC he is pulling the fill out of savings because “it’s not like I can change jobs.” Small margins, small savings accounts, one tank. Every one of them is running the same household math Hannah is running.

The regulator has admitted it out loud. Sarah Cardell, chief executive of the Competition and Markets Authority, says heating-oil customers in remote areas are too exposed to price shocks and that “stronger safeguards are needed — including regulatory oversight and better support for vulnerable consumers.” Read that plainly: the competition regulator is asking for the power to regulate a market it currently has no power to regulate. Corinne Pluchino, who runs Action in Rural Communities England, has put the ask to this month’s budget in the simplest terms available — take the VAT off heating oil and LPG for six months. Without it, she says, thousands of rural people risk becoming the forgotten victims of the energy crisis. They were never on the list. That is not the same as being forgotten.

The government’s answer is a £9,000 grant to switch to clean heat, alongside a “dedicated resilience fund” for areas with higher rates of oil heating. Both are real things to have. Neither puts oil in a tank before February, and a grant that arrives with an installer’s diary in 2028 is not an instrument for a household that cannot afford this winter’s fill.

One more thing about how this price is actually made. Richard Willan, who runs the Nadder Oil Buying Club in Wiltshire, where more than 1,000 residents buy in bulk together to get a better rate, says he is watching the American mid-terms to see whether it moves again. A family in Monmouthshire is exposed to an election in another country because the only market that prices their heat is the global crude market, and that market listens to Washington and Tehran before it listens to them.

This is not a forecast. The cold is here. The £250 is here, and it comes back every time the gauge drops below a quarter. Taylor Swift’s four-word title line — “You’re on your own, kid” — reads to these families less like a lyric than like a departmental statement of policy. Britain regulates the energy of everyone it thought to include. The village was not excluded by accident. It was excluded by a line on a map, and the line has a price, and the price is £550 a tank.