Let me rephrase that: When you can't employ said force in self-defense or the defense of others without an extremely high likelihood (i.e., >99%) of violating many (as in thousands and beyond) others' rights to the quiet enjoyment of their liberty and property, that's where the 2nd Amendment ends.
Implied in the right to keep and bear arms is the right to USE those arms. That you have to go to such preposterous lengths to create scenarios where said use might be marginally justifiable illustrates the magnitude of the problem.
Actually not. The use of arms is subject to all sorts of laws and rightly so. They are dangerous, and must be used in a responsible manner. Irresponsible use is covered under such as "reckless endangerment", assault with a deadly weapon, murder, and so forth. Nuclear devices are different in degree, but not really in kind, in this regard. You have to have a *really* big range to safely test your nukes, and even then there are environmental problems..but then again there is lead pollution getting into the water table in the case of conventional guns and ranges. Again, difference in degree but not in kind.
Now, do I want a nuke, or would I have a clue how to procure one? Heck no. I wish the darn things weren't even physically possible. But E=MC2 is "the law" and it can't be put back in the bottle. Although one can probably argue that the existance of nukes prevented World Wars III, which judging by WW-II verses WW-I, would have been a real pisser, even absent nukes.