The Ausie military is a force to be reckoned with, whatever you might say about the civilians. They’ve made their bones in every military contest involving the US for over a hundred years.
2.5 million Chinese ground forces, including reserves. Australia 42k.
Chinese Air Force has 2500 fighters, the Aussies have 100.
And then compare missiles and nukes? Forget about it.
They would get utterly obliterated. This isn’t something that bravado of the WWI and II Aussie era can even come close to overcoming.
The military of OZ and the U.S. may not be the same as the 20th century.