While in the past the main weapon in war were personal arms that is no longer the case. While ordinary citizens may be able to afford military rifles and perhaps even a missile launcher of some sort this does not place them in a position to effectively oppose a modern army.
A modern army is bringing guns and launchers - but they are also bringing fighters, bombers, artillery, tanks, ships, helicopters, UAVs, etc etc. The prevalence of missiles might increase their tank/helicopter costs but they can shell or bomb a city with impunity.
Crucially a modern army also has logistics. Militias will run out of food and ammunition, the modern army has supply chains replenishing it's stores and it's numbers.
Okay, granted a modern army has many advantages. If a powerful army was determined to destroy Australia it would not matter much whether or not we had guns. Certainly having an army (preferably private) would be much more important than having guns at this stage of a conflict.
However, there is not much point simply bombing a country. At some point the goal is obviously to invade the country and secure its resources. This means the invaders need to have troops on the ground securing targets. It is at this stage that ordinary citizens having guns provides a huge advantage.
If ordinary citizens can fight back with automatic weapons and RPG's it is going to massively increase the costs of invasion and instill fear in the invading soldiers who will at some point have to fight on the ground with small arms. This certainly makes it more likely that they will eventually pull out, or that at least the invaded people can escape without being murdered or enslaved.
Insurgency sure beats enslavement but that's not my point. My point is that a militia is not a substitute for an army. Not that they are a bad thing in themselves - just that they don't live up to the marketing hype that you are giving them.
Agreed, though you make it seem as though the two are mutually exclusive. I never said we should have a well armed population INSTEAD of an army, rather I suggest having both. Since allowing people to own guns costs nothing (in fact it saves money on enforcement of gun laws) it would seem foolish not to allow it, even if the military advantage is not that great (which I still think it is).
It seems somewhat disingenuous then to discuss the ability (or lack thereof) of a militia to oppose an invasion. Under your concept we are already occupied.
Its somewhat disingenuous of you to play semantics about the meaning of the word invasion. It was pretty obvious I meant a military threat to the civilian population. That could take the form of a foreign army or a massive shift in the practices of our own government which would be just as much a threat to our lives and happiness as a foreign attacker.