Modern armies require several things in addition to all of the hight tech wizardry which todays politicians and a few of their appointed generals put so much stock in ... far too much stock I might add.
They require people to operate the high tech gadgetry and they require other people, a lot of them to maintain, feed, provision, load, et. both the gadgetry and the people operating them. Its a thing called logistics.
Simply put, logistics are hell when there are no front lines. Gadgetry that rubs out of juice ... stops working.
Gadgetry runs out of juice quickly when every truck driver, every mechanic, every maintianer, every trainer, etc. is subject to the Rule of 308 and Proposition 223 at anytime and anywhere from 200 to 600 yards.
Gadgetry also stops working when the people operating it, who are educated and themselves free, discover it is being used to kill thier unles, cousins, and fellow citizens.
There are eighty million armed Americans distributed all over this nation. It is estimated that they own something on the order of 500,000,000+ firearms with several billion rounds of ammunition. Those numbers would swallow a modern army up.
Several of the people on this board trying to explain this to you have a LOT of experience in the modern armies you speak of ... perhaps you should listen to them.
Finally, as to the so-called doctrine of original intent and it being highly subject to interpretation. That is true if the people who originally wrote it are not clear in their language regarding it. Some parts of the constitution may be vague (I do not believe the 2nd amendment to be on of them), but the founders were rather verbose in their explanations.
I have not yet heard you answer Travis McGee (and BTW, he is one of those with the experience of whom I speak) and the clear language he posted from the founders regarding what they wrote in the constitution. Where are your quotes from those same founders that would lead to us having to interpret their meaning?
Of course, as an instructor of American Government, I trust that you are including in your teachings the clear language of the men who wrote the basis for that government. If you are not ... then you'd best re-examine your title as a teacher and perhaps consider changing that title to propogandist or deciever or somethiong more fitting to what you are actually doing ... of course, this is presuming you are not sharing with your students that clear language.