In Switzerland, the purpose of the second amendment is on display. It's cantons are each prepared against invasions that nobody in Switzerland ever expects to happens, but they are prepared to keep their neighbors neighborly. The concept behind the second amendment was invented in places like Switzerland. The purpose of the second amendment was to avoid a standing army by having a strong militia. (http://www.snopes.com/politics/guns/switzerland.asp). In Switzerland all the males are drafted. In the USA we have the National Guard, and then we have militia which often are no better than USA Nazi or fascist Brownshirts. I beleive we need to bring back a nationally organized militia to avoid the brownshirts and to strengthen democracy. If we want that, maybe we need to imitate the Swiss.
In Israel they have a similar system, though they exempt too many people from it. Israel would be well off imitating the Swiss. The Swiss have multiple religions that once were at each other throats. Originally the militia also had the job of protecting Swiss protestants from Swiss Catholics as well as from outsiders. A secular militia enables freedom of religion by encouraging people to distinguish between tribal and religious identity -- and national or civic identity. If everyone is Swiss; Buddhist, Christian, Moslem or Hindu, first, then there is no reason to kill as "Non Swiss" folks who are not one's own sectual preference.
Teaching civic identity and civic values is part of establishing and maintaining civilization. Civitus versus "tribus" is the reason the concept of "civitus" was invented in the first place. You can't have functional markets or urbanity without the ability of many disparate people coming together under uniform laws to trade and exchange. Sorry but markets might govern themselves, but they have to have a government to exist. It may look like anarchy, but the regulations, the uniform weights and measures, the money that can be trusted, etc... are all features of government. And if everyone was trained in how to use a fire arm and the principles of our democracy, that would be a civil government. "Secular humanism" isn't opposed to religion, that is a modern myth. Secular humanism is just an expression of the concept of "civitus" taken to modern times.
Maybe, we need to bring back the militia, with a uniform "basic training" so that young adults can grow up together and responsibly use fire-arms. And they would need to have a license as a result -- and only those with such a license should be able to acquire one. So if someone has a gun, it is secured according to regulations, used by someone who knows to empty the bullets out before cleaning it, etc...
Criminals sometimes move outside the law on their own, but often they are pushed there by exclusion from legitimate society. The concept of civitus is around the notion we should pull them into our comity and create a civilization rather than warring communities and tribes. Even tribal communities usually have something like that. They take the kids, train them, run them through an initiation ceremony and after that they are adults, act like adults, feel they are adults and usually are ready to be adults. Militia plays that role in civilized societies on a larger scale.
And Militia is part of how modern democracy got started, and ancient democracy. The first step to democracy is the general assembly. And most general assemblies were initially of men who could fight to defend a town or village. An army can provide a rough democracy to a town and in ancient England the Yeomanry won their rights because their arrows and weapons were necessary to the survival of the British Crown in it's wars and civil wars. They won rights by being able to fight for them, and then not having to do so, because the official government; barons, clerics and officials -- had to respect them.
Representation usually came with the ability to provide armed forces as well. Our militia made the difference in our revolution against the British, but it was the unity of it, and it being led by a trained officer corps that made the difference. Hence the words "well regulated militia" in the constitution. We've had a standing army due to external wars, but if we weren't constantly war-mongering at the behest of war-profiteers we wouldn't need such a standing army. And we've traditionally drawn our standing army by drafting people who spend the rest of their obligation in militia. Police, fire, rescue, all have their origins in militia. We need to have a stronger National Guard, and train people so they can be part of our society -- and that starts with training them to be in a militia. It doesn't have to be an armed militia; fire brigades, flood brigades, medical brigades, even science and health brigades, could fill the bill too.
So we should use the National Guard, strengthen it's functions, and include within it medical corps, first responder training, fire and rescue training, first aid. All the stuff folks like me learned as a boy scout. And use that institution to create a real bottom up institution to involve our young men in our society.
Anyway, I'd take most of our guns, the heavy caliber ones, and move them to armories, that would just also happen to be associated with community centers, firing ranges, and where people could learn to fire a gun, and if they wanted an AK-47 or AR-15, keep it in a gun locker under control of a Sargent there. Then should there be a disaster they'd be the first responders, not some invading army. And if someone wants to play with his assault rifle, he can do it some place where he's not going to hurt anyone. Or she.
We need a smaller standing army, but a larger commitment to militia and to training our young people. Now I'd organize it on a membership basis, with National, State, county and local member branches run by full time soldiers, backed by a membership organization where militia members would have a voice in their own affairs with elected structures and general assemblies. The right to assemble is in the constitution for multiple reasons.