Canada has all but the liability insurance and they are 12th in the world in guns per capita. The problem isn't even American laws. The problem is American culture that feeds into a small percentage of the population owning an obscene amount of guns and American culture that feeds into the idea that protecting your property is equivalent to protecting yourself.

You could cap American gun ownership to one rifle and one handgun per person and the amount of guns in circulation would massively decrease so that per capita rates are similar to other western countries but the amount of gun owners won't change.

And you could put all the licensing in the world in place but it won't change the fact that American culture believes massively in self-protection of a person, even if their life is not in danger, and their property to be allowable uses of guns. When given the choice between having a TV stolen or having the thief shot, laws favor having the thief shot. Many other countries favor the opposite -- that you should kiss your TV goodbye and instead ensure you have good property insurance.

And that concept -- that guns are for self-defence of all things, including property -- is what feeds into the mindset that guns are a solution to perceived wrongs done to someone. Crazy people just take that same mindset and take it to the extreme. It all feeds from the same culture.

Now, I am not saying that this culture is right or wrong. It is what it is. But it is important to recognize that it is at the core of this all, not the second amendment. No one is concerned about rifles owned by hunters or farmers that live in a wildlife interface. It is the guys with 5+ guns in their house "just in case."