As Tartare said - "that if a war wrecked and (at that time) artisanal economy like Britain can progress to a full CASD in ~20 years, then I reckon Australia now and in future is certainly technically capable of doing."
You might also look at N Korea - a genuine economic basket case, Israel - not a vast industrial complex, Pakistan & India - probably roughly equivalent to the UK around 1950 at the time they started building a bomb. The technologies are well known - the question is do you have the political will and sticking power to divert a very large amount of national wealth and expertise for a decade into building a bomb?
Looking at the current users you'd say you'd have to face a clear and overwhelming threat to the very existence of the the nation. I don't think the Australian public sees China in those terms as yet