Gnadenburg
Not a conventional navy but here's a hypothetical. How would you stop a thousand fishing boats full of soldiers headed to Darwin. The ADF couldn't hope to stop them all.
As for India and China, its not just their arms build up. Both are countries who aspire to things like a space program - in fact China was the third country to launch an astronaut into space. India is busy creating an IT and service industry to take outsourced jobs from western countries - and still both receive foreign aid from Australia.