A bit of simple arithmetic is needed to explain why the closing of the Strait of Hormuz could destroy the economies of Australia and New Zealand.
Both countries rely on imported refined product from Asia. New Zealand is wholly dependent while Australia is about 90% dependent. China has ceased exporting product, so cross them off the list. That leaves, for the most part; South Korea, Singapore and Malaysia.
South Korea processes up to 3.4m bpd (million barrels per day), 2.5m of which is consumed domestically. 70% of their supply comes from the Middle East.
Singapore processes about 1.5m bpd, and they import 70% of their oil from the Middle East.
Malaysia processes about 900,000 bpb, and they import about 40% of that oil from the Middle East as they have their own oil wells. Domestically, they consume about 77% of the total and export the rest.
I trust you may begin to see the problem. With a huge amount of Middle Eastern oil coming through the Strait shut off, these economies will need to prioritise their own market first, and even then they'll come up short.
South Korea has begun buying oil from Canada, about 800,000 barrels per day. That's well short of the 2.4m bpd needed. They can only just supply themselves, leaving nothing to export.
Singapore looks set to lose 1.0m bpd, and that equates to the daily consumption of Australia. Forget NZ, they'll just be left to fail.
Malaysia, just to supply its own needs, will have to import from other sources, just as South Korea is doing.
All of this adds up to a very serious predicament Downunder. I see the Philippines has declared a state of emergency, and that is a wise thing to do. Australia and New Zealand need to follow suit as this war in the Middle East could drag on for a long time, that much is obvious.

