By calling attention to 'a well regulated militia,' the 'security' of the nation, and the right of each citizen 'to keep and bear arms,' our founding fathers recognized the essentially civilian nature of our economy. Although it is extremely unlikely that the fears of governmental tyranny which gave rise to the Second Amendment will ever be a major danger to our nation, the Amendment still remains an important declaration of our basic civilian-military relationships, in which every citizen must be ready to participate in the defense of his country. For that reason I believe the Second Amendment will always be important.This is where the phrase "well regulated militia" comes into play. In military parlance, "regulated" refers to efforts to make an army of men more "regular":
John F. Kennedy, 1960
...being commanded by a person responsible for his subordinates to a party of conflict, and
...having a fixed distinctive emblem recognizable at a distance, and
...carrying arms openly, and
...conducting operations in accordance with the laws and customs of war
In other words, part of being a "regular" force means that person is trained, equipped, and commanded according to standardized procedures. When "well regulated" is paired together with "militia", or all able-bodied men between 17 and 45, it seems clear that the intent of the Founders is that civilians are supposed to have military style "assault" weapons, so as to better be able to integrate seamlessly into the regular, standing army when called upon.
This is likely hard to do if civilians are not permitted to possess or bear "assault" weapons in the first place. The notion that scary black guns are reserved for military / law enforcement only pretty much flies in the face of a straightforward reading of the Constitution. Rather than banning black rifles, we should be issuing them.
The second reason why civilian firearms ownership is key is not because of opposition to tyranny--a concept that understandably gets liberalists all riled up, seeing how Leviathan is their middle name and tyranny is their game--but because civilian firearms ownership precludes the "need" for a strong muscular state in the first place. It also keeps the people secure in the gaps between the State and the private citizen...or when the State either cannot be for budgetary reasons, or declines to be for reasons of personal convenience. Remember, the police have no duty to protect/serve, and a standing army of professional LEOs costs money to organize, train, equip, and field. Money that municipalities, states, and the FedGov increasingly does not have.