Australia imports roughly 90% of its refined fuel; New Zealand imports 100% of its jet fuel since Marsden Point stopped refining in 2022. Both arrive through straits a rival can close — and as of February 2026, one is closed. The tempting move is to turn curtailed renewable surplus into synthetic jet and call it independence. Inari's comparator refuses the romance and asks the harder question: per dollar, does building fuel buy more security than storing it? The answer reorders the whole conversation — and it is not the one the pitch decks want.
A rare-earth magnet takes a paragraph to justify. Fuel security takes a sentence: the tankers stop, and within weeks the country stops. Australia holds around 50 days of diesel-and-jet cover — shorthand for how many days of normal demand a stockpile alone could meet — it is now racing to build, refines fuel at just two remaining plants, and depends on sea lanes running past the Malacca and Hormuz straits. New Zealand is starker still — no refinery, one import terminal, a single pipeline feeding Auckland Airport whose 2017 rupture grounded flights nationwide. This is not a modelled risk. As of 28 February 2026, the Strait of Hormuz — roughly a quarter of the world's seaborne oil — has been effectively closed, and Australia has responded with a A$3.2 billion Fuel Security Reserve (Australian dollars; a government fund built to stockpile emergency fuel) inside a fuel-security package of up to A$11.9 billion.
Australia and New Zealand don't make most of their own jet fuel — they ship it in past places a hostile navy could block. Right now, one of those places is blocked. So the government is spending billions filling tanks. The question this page answers: would we be safer spending that money building fuel factories instead?
That live crisis is the exhibit. It also happens to be the cleanest natural test of the comparator below — because it shows us what a government actually does when the strait closes. It does not break ground on synthetic-fuel plants. It buys tanks. The model explains why that is the right first move — and exactly where it stops being enough.
The comparator prices two ways to survive a disruption of length D days. A stockpile is a stock: buy N days of cover once, deploy it to bridge the gap, then it's dry — cost roughly linear in days. Domestic production is a flow: each 100 kt methanol-to-jet line supplies a fixed ~0.55% of daily demand, forever — so covering the nation's jet flow takes about 179 lines, regardless of how long the disruption lasts. Forcing the two into one unit flatters neither; the model instead minimises annualised cost to hold a coverage target through D days, choosing the cheapest blend.
The decisive variable turns out to be how much of a plant's cost its peacetime fuel sales already cover. Call it commercial credit. At credit zero — a plant built purely for security — the crossover where production finally beats the tank is decades away:
| Commercial credit | Crossover D* | Reading |
|---|---|---|
| 0.0 · security-funded | 31.5 yr | Never, on any realistic contest |
| 0.5 · half-commercial | 15.7 yr | Never |
| 0.9 · mostly commercial | 3.1 yr | Only a multi-year contest |
| 1.0 · fully commercial | 0 yr | Resilience is free — always build |
Exhibit · kata/sovq/comparator.py on locked ledger params · stockpile-carry band moves D* to 20.1–67.4 yr at credit 0 — direction invariant. Falsification (the test that could prove this wrong): the model is a linear corner-solution; it omits rationing, demand-destruction and plant learning-rates. These move magnitudes, not the sign — 179 lines for full flow is arithmetic.
If you build fuel plants only for security, filling tanks is cheaper even through a thirty-year blockade. The maths only flips when the plants already pay for themselves selling clean jet in normal times — then the security comes free. So sovereignty isn't a reason to build; a profitable clean-fuel industry is, and the security rides along.
Production is not useless — it does one thing a stockpile physically cannot: it keeps supplying after the tank runs dry. That tail is worth paying for in exactly two structures, and the model names both.
Inari does not tell a government to build a fuel industry to defend itself; the numbers won't carry it. It outputs an ordering: stockpile the shock (the tank is correct, and it is what governments already do); back a commercially self-funding clean-fuel industry so the flow scales as a co-benefit; fund a small physical defence core on the assured-supply premium; and structure every molecule physical-plus-Guarantee-of-Origin, never book-and-claim. Siting follows curtailment depth against biogenic carbon (carbon from recent plant matter, not fossil sources — the feedstock needed to make synthetic jet fuel) and jet infrastructure — Portland in Victoria, Marsden Point in New Zealand.
Fill the tanks first — that's the cheap, fast safety. Then help a clean-jet industry stand up on its own commercial legs, and the country quietly gains a factory that keeps running when imports stop. Pay for a few plants outright only for the military. And insist the fuel is real barrels made here, not paper certificates.
燃料主権 — sovereignty measured in days can be bought; capability measured in a warm line cannot. The comparator prices the first honestly and refuses to fake the second.