I think the answer to that would be there is no guarantee that a government will or will not turn against its citizens. If one looks at the massacres in the Soviet Union, Hitler's march across Eastern Europe, China under Mao, Pol Pot, Idi Amin and countless other genocidal tyrants one could certainly say the victims would certainly have been in a better position to fight back if they were armed.
If one looks at all of history, human freedom is not the norm rather the exception. All of the above took place in living memory of many alive today. First the public were disarmed then massacred.
Another difference between the US and Australia is the second amendment- good luck with that.
The main issue in the USA is people keep saying do something but they cannot come up with viable suggestions to counter gun violence. Banning automatic weapons would make no real difference as the vast majority of US gun killings take place with handguns in predominately Democrat-controlled African-American neighbourhoods.
Quoted by a random Texan gun moll:
" Q: I have 11 guns. Obama wants to take my guns. How many guns do I have?
A: I have 11 guns"
