To realise how silly we are, in being USA's lap dog, consider: 1) Australia vs Japan 2) Australia vs Indonesia.
USA claims to have all three countries as it's allies. Therefore, why would USA defend us against another of it's allies?
So many possibilities, such as: We are under attack. In desperation, we accept China's offer to base modern fighters and missile defences on our soil, while USA is paralysed with indecision. Post conflict, we feel secure in our new military alliance with our new best buddy....China.
Best buddies aren't needed if a nation accepts the cost of being ever vigilant and prepared. We could easily build all our defense equipment 'in house' but the bulk of our population and political class do not accept the premise of being strong and independent in our defense thinking and planning.
We could build a much better aircraft than the F35. Even building a copy/update F111 airframe as a fast, long legged and high flying munitions truck would be pretty useful and survivable. High and fast tends to defeat stealth. Maybe licence build a chosen Sukhoi model.
Surely we could design and build a tough battlefield aircraft, in the A10 mold.
Too expensive? Nah. No more costly than what we are proposing to waste on the mission incapable F35.