I find it hard to believe the the 2nd Amendment is exclusively for national defense

[jimmy the one]

21. miller 1939

N-unicorn: I'm not seeing that as a refutation of my premise.

There are several aspects to your OP premise, but if you say so, you seemingly disagree then with lizzie poppet.

tench coxe 1788: Who are the militia? Are they not ourselves? .. Congress has no power to disarm the militia. Their swords and every terrible implement of the soldier are the birthright of Americans. The unlimited power of the sword is not in the hands of either the federal or state governments but where, I trust in God, it will always remain, in the hands of the people.

N-unicorn 2013: That encapsulates my point exactly.

Then you agree that coxe was referring to the people as the militia, my underlying point.
Perhaps the Supreme Court UNANIMOUS 1939 ruling in the Miller case will help convince you, or elucidate: Miller, 1939: "The Constitution as originally adopted granted to the Congress power - 'To provide for calling forth the Militia to execute the Laws of the Union'.... With obvious purpose to assure the continuation and render possible the effectiveness of such forces the declaration and guarantee of the Second Amendment were made. It must be interpreted and applied with that end in view."

This was a unanimous 8-0 ruling, all the ruling justices felt this wording was proper, with no objections. The heller decision was split along political lines, 5-4.