[x5452]

The second amendment was designed so that the people could take defense against a tyrannous government, as they had just done against england, and has nothing to do with government run armies, regardless of naming semantics.

[RKV]

The militia (as opposed to the army or select militia [now the National Guard]) has three constitutionally specified missions. Article 1 Section 8 (on the legislature) says Congress can "calling [sic] forth the militia to [1)]execute the laws of the union, [2)] suppress insurrections and [3)] repel invasions." The Federalist Papers deal with the issue you describe - defense against tyranny.