What country was successfully invaded and taken over by an airforce? none.
troops have to take and hold ground. Not easy to do with 105 Million armed civilians. You need to take all the 300 Million guns back first. I do not think you understand this point. One could argue that the 2nd is MORE about protecting the country from FOREIGN invaders than its own government. Read it.
Invaded and taken over? None.
I'd say that Japan could give you two reasons why an Air Force is quite helpful in winning a war without the need to invade.
As for the text, I think it's pretty clear that it was intended for securing a free state regardless of whether those infringing on those rights were foreign or domestic. I agree to your points, and I kind of think we are saying the same thing, but thinking about different scenarios. I don't think anyone could occupy the USA, except the US Military. I don't believe that our country doesn't have enough people with the stones to actually overthrow the government.