America refines more diesel than it burns: about 5.3 million barrels a day against about 3.6 million used at home, with the rest sold abroad. Yet on 22 September 2026 diesel at American pumps hit a record $6.53 a gallon, and California passed $8. The war with Iran had closed the Strait of Hormuz since February; in July Russia stopped selling diesel abroad.
The obvious fix went around Washington: stop exporting diesel and keep it at home. A bill in Congress would switch a ban on automatically whenever the national average reaches $5. Then a Dallas Fed economist, Garrett Golding, warned that a ban could make diesel more expensive in New York. How can keeping fuel at home make it dearer at home?
Picture the country as one big tank with a tap on the side, where the surplus runs out to ships bound for Mexico, South America and Europe. Close the tap and the level rises; in that picture the price falls everywhere at once.
Golding's warning starts with the rest of the world. By September 2026 American diesel exports were running at about 1.6 million barrels a day. Pull that out of a world market already short of diesel and the world price jumps — and it comes back like a boomerang to the parts of America that buy fuel from abroad, the East Coast most of all.
The East Coast imports only a small share of its diesel, mostly from Canada. But a Canadian refinery can sell to New York or to Europe, so New York has to pay what Europe would pay. Why would any corner of a country with a surplus pay the world price at all?
Because it isn't one tank. No pipeline carries fuel from the Gulf over the Rocky Mountains; California lives mostly on its own refineries, and a tanker from Texas needs about ten days through the Panama Canal. That is how California paid over $8 while the country paid $6.50.
The East is connected through one enormous pipe. The Colonial Pipeline runs from Houston to the New York area, and its diesel line carries about a million barrels a day. For years before this crisis the Energy Information Administration described it as running at or near full. More diesel in Texas does not make it wider; its rules only decide which companies get the space that exists.
That leaves the sea, where a law from 1920 applies: any ship carrying cargo between two American ports must be built in America, owned by Americans, flagged American and crewed by Americans. A foreign tanker may carry Texas diesel to Rotterdam, not to New York. In 1950 more than 400 ocean-going ships qualified; in the last official count, for 2018, about 100 did, fewer than 60 of them tankers.
On 17 March 2026, at the request of the military, the Department of Homeland Security suspended the 1920 law for fuel shipments and later extended the waiver. In April, diesel moving by water from the Gulf to the East Coast hit a record of about 220,000 barrels a day — and East Coast prices kept setting records anyway.
That shows when the lane matters. As long as Texas sells to the world, Texas diesel costs about what world diesel costs, and a cheaper ship changes little: economists Ryan Kellogg and Richard Sweeney put the 1920 law's normal-times effect on East Coast diesel at about two cents a gallon, because most of it arrives by pipe. In the war market of 2026, by one Jones Act operator's count, a foreign tanker from Houston to New York even cost slightly more than an American one.
But on the day the tap closes, Texas diesel becomes cheaper than world diesel, and the only question is whether it can reach New York. A ban with the lane open lets the relief travel; a ban with the lane shut keeps it in Texas.
For the Northeast there is a reserve, in place since 2000: the Northeast Home Heating Oil Reserve, held in tanks in Maine, Massachusetts, Connecticut and New York Harbor. On 22 September 2026 Maine's two senators asked the President to open it; heating oil in Maine cost about three quarters more than a year earlier.
Congress first sized it at two million barrels, about ten days of the region's heating oil at the time. In 2011 it cut it to one million — about one day of what the Colonial diesel line carries, and a few days at the height of a cold snap.
Opening it has a rule: the President must find a severe supply interruption, and for a price spike the heating oil margin must stay more than 60 per cent above its five-year average for seven days in a row, still rising, and only between mid-October and March. In September it could not be opened for price at all. In its first quarter century it was drawn on once, after Hurricane Sandy in 2012, and never for a price.
The tap. A ban, perhaps with an automatic trigger like the $5 bill. Russia banned diesel exports in July 2026 to protect its own supply. Analysts expect Gulf and Midwest prices to fall by tens of cents a gallon — real money for farmers and truckers there. Price: refineries that cannot sell diesel run slower, so less gasoline and jet fuel; Mexico, which gets more than 100,000 barrels a day of US diesel overland, loses a supplier with its own stocks under a week; and a Dallas Fed study of a similar crude ban called it "not only ineffective, but also counterproductive". The White House said at the time that no ban was under consideration.
The links. Rewrite the shipping rule, which would also let any future ban reach the coasts. The EU let any member state's ships carry cargo between its ports in the 1990s; Canada lets a foreign ship in only when no Canadian one is available. Reformers argue the law's real cost is the coastal shipping that never happens. Price: the ships and mariners the military can call on — in 2018 the Maritime Administration estimated a shortage of about 1,800 mariners for a long mobilisation, and by the American shipping industry's own study almost a quarter of the ships used under the 2026 waiver were built in China.
The reserve. Make it big enough to matter — weeks, not days — with a trigger that can fire outside winter. EU law already requires member states to hold oil stocks of at least 90 days of net imports. Price: about $6.5 million a year just to run today's million barrels, and well over $100 million of diesel for every extra million; an easy trigger invites politically timed releases and lets private suppliers keep thinner stocks. And a reserve does not change the world price. It buys time, not cheap fuel.
The debate in September 2026 was framed as yes or no. But the ban and the links are not rivals: one decides whether the other works. And the links were set long before this crisis, by Congress and a federal regulator.
When someone promises to lower the price by closing a tap, ask which tank fills up when it closes — and who decided how wide the connection to yours would be.