... Congress has supervisory authority over the armed forces generally, but the authority to train the militia and appoint militia officers is reserved to the states, provided they conduct that training "according to the discipline prescribed by Congress." Congress also has power to provide for calling the militia into federal service, meaning that Congress can federalize the militia of one or more states or pass legislation authorizing the president to call the militia into federal service.
One more provision of the Constitution deserves our attention — the Second Amendment: "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
The reference to the militia states a reason for the right to bear arms, not a condition thereto. Note that the word "people" is not used interchangeably with the word "state," and that the term "keep and bear arms" implies individual ownership of weapons. Collectivists have argued that the Second Amendment protects only the right of the state to maintain a military force. However, in the 2008 District of Columbia v. Heller decision, the Supreme Court ruled 5-4 that the amendment protects the individual citizen's right to bear arms (although the court also errantly said this right is subject to state regulation).
One purpose of the militia is to defend the liberty of the people against foreign invaders. Throughout history it has worked effectively, and it still works today. In "The Rationale of the Automatic Rifle," Massad Ayoob recounts part of a conversation that took place when Cmdr. Robert Menard attended a 1960 meeting between U.S. Navy personnel and their Japanese counterparts. One American naval officer asked why the Japanese did not invade America's west coast during WWII. A Japanese admiral answered: "We knew that probably every second home in your country contained firearms. We knew that your country actually had state championships for private citizens shooting military rifles. We were not fools to set foot in such quicksand."
But the militia serves another purpose: the defense of the people's liberty against domestic tyrants. To many Americans today, this thought seems radical and almost subversive. But consider James Madison's words in The Federalist, No. 46:Let a regular army, fully equal to the resources of the country, be formed; and let it be entirely at the devotion of the federal government; still it would not be going too far to say, that the state governments with the people on their side would be able to repel the danger. The highest number to which, according to the best computation, a standing army can be carried in any country, does not exceed one hundredth part of the whole number of souls; or one twenty-fifth of the number able to bear arms. This proportion would not yield in the United States an army of more than twenty-five or thirty thousand men. To these would be opposed a militia amounting to near half a million of citizens with arms in their hands, officered by men chosen from among themselves, fighting for their common liberties, and united and conducted by governments possessing their affections and confidence. It may well be doubted whether a militia thus circumstanced could ever be conquered by such a proportion of regular troops.
And Alexander Hamilton, a continental colonel but hardly a wild-eyed revolutionary, expressed a similar thought in The Federalist, No. 29:Little more can reasonably be aimed at with respect to the people at large than to have them properly armed and equipped;... This will not only lessen the call for military establishments; but if circumstances should at any time oblige the government to form an army of any magnitude, that army can never be formidable to the liberties of the people, while there is a large body of citizens, little, if at all, inferior to them in discipline and in the use of arms, who stand ready to defend their rights and those of their fellow citizens....
During the 1950s, several governors objected to their guard units being federalized and called out of the country. Who, they asked, is going to man the armories or do riot or flood control, if the guard is engaged elsewhere? Congress responded in 1956 by adopting 32 U.S.C. § 109, titled "Maintenance of Other Troops," which provides that(c) In addition to its National Guard, if any, a State or Territory, Puerto Rico, the Virgin Islands, or the District of Columbia may, as provided by its laws, organize and maintain defense forces. A defense force established under this section may be used within the jurisdiction concerned, as its chief executive (or commanding general in the case of the District of Columbia) considers necessary, but it may not be called, ordered, or drafted into the armed forces.
The act also provides that enlistment in a state's defense force shall not exempt a person from the draft, and that a person may not belong to a defense force if he is already a member of a reserve component of the armed forces. ...
Read the article here.