The problem with it is simple:
How to get from where we are right now to a world where governments and criminals don't plunder and murder people en masse?
The answer is to allow people to acquire the tools and technologies to protect themselves and their property.
And articulate a set of laws and ethics in the political sphere that applies to both governments and common thieves, gangsters and murderers.
Civilian murder by any government in the name of war is simply unacceptable, no matter what numbers and statistics we are talking about. Same goes for non-government criminals.
Simply saying 'government needed' is not adequate. It lacks depth.