Many have argued that civilians have no business owning “military” grade firearms, such as the venerable Colt AR-15 (the civilian semi-automatic version of the military’s fully-automatic M-16). The argument goes that when the the 2nd amendment was written muskets and muzzle-loaders (single-shot rifles that can take up to a minute to reload) were all that was available, and so that’s all private citizens should own. I disagree.
The second amendment was meant to ensure that the power remain with the people. Specifically, that a standing army acting at the behest of a potentially despotic government could never be as powerful as the body of the people, given the people were properly armed and equipped to defend against such a force. At the time of the American revolution the arms necessary were the same as those possessed by the British military: muskets and muzzle-loaders; today, those same arms would be equivalent to the AR-15 or M-16.
That’s not to say that all military arms need to be available, or even that fully-automatic arms like the M-16 be common implements of a citizen militia. It was always expected that the military would never comprise more than a small segment of the population, and that the balance of the citizens when properly armed would be a formidable opponent for any army the government might muster. However, sending the body of the citizenry armed with muskets against a military force armed with M-16 rifles – well, that is hardly a win-able fight, no matter how many citizens you have. Being armed with a semi-automatic version of the M-16 (the AR-15), however, would allow a citizenry a reasonable chance at success. Thus, without a military arm – if not slightly de-tuned from the full military specification – the power would not remain with the people, as they would easily be defeated no matter their numbers.
If you want to re-arm the military in the United States so that their arms are no more formidable than the arms available to the people, then so be it: give the military muskets, and I’ll take one, too. That will likely make the matter moot, however; it is unlikely that other governments would bother to honor our sovereignty when we could no longer defend ourselves against their M-16 rifles.
From the Federalist #28 (widely attributed to Alexander Hamilton):
If the representatives of the people betray their constituents, there is then no resource left but in the exertion of that original right of self-defence, which is paramount to all positive forms of government…