I guess the question is where are you going to fight and who are you fighting?
It's hard to see the Red Army ploughing through Indonesia so you're thinking of fighting the Chinese Navy and Air Force somewhere north of Indonesia & PNG. You have to ask if that is likely or effective unless you are fighting alongside the USA - in which case Australia is going to be a bit of a side-show to the main action which will take place much further north - Taiwan and the N Pacific