Unfortunately, short of a civil war, Australia appears to be lost. We all know, the most powerful and destructive weapon is the human mind and that's why it is as pointless as pissing in the wind, to ban any item that may be used as a weapon. There's always a better one within arm's reach, more, or less, because ANYTHING can and will be used as a weapon.
Human populations reaching critical levels of complacency and comfort leads to catastrophes. There is a reason why Elon Musk is so hellbent on starting the Mars phase of the next step in human exploration. If you look at EVERY company he has founded or has acquired, it has something to do with Martian colonization.
SpaceX: Getting there, and heavy materials and large occupant capacity transportation between Earth and offworld assets.
Hyperloop: Contactless magnetic ground transport between Mars outposts and getting around the planet in general.
X/Twitter: Telecommunications and data processing.
Starlink: Planet-wide data interface, as well as interplanetary communications.
Tesla: All vehicles used in Mars and offworld sites will have to be electric.
Neuralink: Human-computer interface enabling for enhanced human senses and instant, synced in data support for the existing 5 senses. Would be essential for construction workers, scientists, and security forces operating in space or hostile atmospheres. Also enables humans to directly interface with and operate drones, robots, etc.
The last time humanity has reached a near critical population and complacency period was during the first Age of Exploration. Europe during the time of Columbus and Magellan was beset by horrific religious wars that claimed millions of lives, and theocratic oppression which saw scientific advancements halted and leading scientists forced to renounce their discoveries on the pain of torture and death. The New World enabled the tough, adventurous, and hardy to leave that world behind and found which would eventually become the USA and other places.
We are reaching this 1450s-esque critical mass again where a large percentage of people have willingly neutered themselves and allowed themselves to become defenseless sheep, while a minor percentage only seeks to obtain total control and compliance. And in the midst of all this, there are pockets of hardy and tough individuals just like in the Old World, but not in enough strength to overthrow or alter the rapidly declining facets of current society through force of arms alone.
So the only viable and pragmatic solution for the future, would be to branch out again, just like what Columbus, Drake, Cortez, Pizarro, and Balboa did. The "oceans" would be a lot more bigger, and empty this time, but in order for terran civilization to survive, it seems like at certain epochs, at least a portion of the human population must branch out, settle new domains, and return to a state of survival minded toughness paired with adventurous attitude so old ideas and mentalities which allowed humans to survive the Ice Ages can continue to thrive.
