To invade Australia, one would take Tasmania and use it as an Aircraft Carrier. That possibility is still on the books and included in current strategy.While the bulk of Australia's forces are on the southeast coast, there are many bases on its north coast, both empty and used especially near its northern city of Darwin. Much of the Australian forces have as much distance to travel to meet any Indonesian threat as Indonesia. There isn't much in-between, but harsh desert. Indonesia faces seas which don't have much of anything either.
Any amphibious threat will be engaged before the threat ever reached the shores of Australia. F-117s don't have much more range than a Hornet, Super Hornet, and/or Lightning II. Yes, the F-111's range will be missed, but with air tankers the range don't matter anymore.
However, if you could take out Aus and NZ airforces, before the US could get Phillipines/Japan/Coral Sea assets going, you could invade with 20,000 troops and hold the joint for a fair while.
We are lucky that we are surrounded by millions of square miles of nothing, any threat from marine forces would be detected that far in advance it wouldnt be funny.
I spose you could try and hide 20,000 marines in a Car Carrier, but even that would be detected before it began thanks to technology.
We do not share any land borders, so we are immune from conventional incursions/invasions.
It was good to read that the new Govt. is considering considering scrapping the order book and starting anew and will contemplate looking at Sukois, but as we all know, that would never happen.
I just want us to stop falliing for all this second hand crap we keep buying and buy the best available for the job, be it a plate or a plane.
We have decided to play in the big boys game, so we have to cop the cost.