based on your argument Australia cant get a nuclear sub to protect its trade routes as it upsets chinaI've made it pretty clear, and so has AUKUS, that this is intended to be a regional defence strategy. Australia alone couldn't defend itself against Indonesia if they really wanted to wander across the sea.
We have subs, missiles and jets to contribute to assist others in the region and provide joint deterrent.
What's the alternative? Just let the USA and China dominate the world and the rest of us might as well not bother with a military because we'd lose against our largest enemy? And if North Korea invade South Korea again, we just shrug our shoulders and say "well, we would have had a military, but China could have just beaten it, so we didn't bother".