Aussies love to blame colluding petrol companies and high taxes for our high petrol prices. Fair enough -- there’s substance to the accusation. We have few fuel retailers, and they seem unusually gifted at getting their prices to move in sync. Meanwhile, excise is a hefty chunk of what we pay at the pump -- 41.2 cents per litre on unleaded.
But when petrol prices rose toward $1.70 last month -- higher in some places -- it became harder to blame domestic factors. They may be substantial, but they are steady. Great swings in petrol prices are almost always due to international meddling, and this time the fault lay with Donald Trump and his plan for Iranian sanctions.