3. Energy Security
Most all of our energy comes from the sun. The sun's energy heat the oceans, leading to high-elevation precipitation that feeds our lakes and streams, and fills our reservoirs (to power our generator dams). The sun's differential atmospheric heating leads to the winds that can be used to extract energy through wind-turbines. Over countless millennia, the sun's energy powered the photosynthesis of low-energy minerals into complex high-energy carbohydrates, through plants whose many trillion-ton biomass has left residues we burn as coal and petroleum.
Everything that runs, runs on energy. The growth of our crops, the machines that process materials into goods, the vehicles that move those goods to markets, the heating and cooling of our homes and businesses, the refrigeration of our food stores, the lights that allow us to operate after hours, and of course the ability to communicate and process information - these ALL require energy in one form or another. A conquering adversary would certainly want to disrupt the people's access to energy, and a government headed towards tyranny (not to mention, energy corporations headed towards higher profits) would prefer a populace dependent upon highly centralized and "controllable" forms of power generation.
Aside from firearms, the one "defense-in-depth" capability a free people should demand is the guaranteed access to local power generation. If we are not to trust our future security only to our centralized armed forces and their armories, why would we allow ourselves to be held hostage to highly centralized and distant power facilities?
Even if wind and solar power were insufficient alone to serve all of our local energy needs, home wiring that differentiates high-amp circuits (for heating, air conditioning, washers and dryers) from low-amp circuits could shut down the high-amp side in emergencies involving distant grid power, allowing (say) led lighting and communications (TV, phone, Internet) to continue uninterrupted in every home. Should a "blitzkrieg" attack take out our centralized energy facilities, nothing will lead to widespread fear, panic, and anarchy faster than millions of homes left for weeks in the dark, with no access to information as to what is happening around them and elsewhere. In contrast, a populace that retains power for communications can remain calm and plot effective response and mitigations.
Among the world's repressive regimes, it "makes sense" to allow the populace only centralized and "controllable" access to food, communications, energy and transportation (and arms? Forget about it!) For such regimes, "national security" means the security of the ruling elite, not the security of the populace. Such restrictions are explained to the people as measures taken "for their own safety", for which they should be thankful. But for a democratic "government by the people", the defense-in-depth afforded by having significant control of such facilities in the hands of the people at the "grass-roots" level should hardly be a matter of debate.
"The availability of energy being critical to the functioning of a free society, the right of the people to local power generation shall not be infringed."
Local energy generation can even extend to localized facilities for refining waste plant matter and vegetable oils into liquid fuels, for power generation when solar and wind are uncooperative. But once again, do take note that having millions of smallish energy generation facilities distributed among the communities will lead to safety concerns you would not generally face with much larger, distant facilities. You always trade some short-term safety for longer-term security.
4. Transportation Security
Personal motorized transportation is yet another factor of the "defense in depth" in securing liberties against oppression. In this country at least, it is a strong symbol of individual freedom - the freedom to find and engage employment far afield of your place of residence, to visit in person with a far greater range of fellow citizens, to move goods about in support of commerce, and if need be, to travel far and wide when local situations might devolve into serious danger. Of course, in a real battle with adversary forces, the availability of individual and private transport, to move personnel, supplies, and even arms, could well become critically important.
And what price do we pay for this motorized freedom? Most every day of the year, approximately 100 men, women and children die in automobile collisions. Granted we have done much to improve these statistics over the years, and will continue to make safety improvements. But this does not diminish the point - we "tolerate" a massive hit to our daily safety in order to afford the freedoms of personally-controlled motor travel.
We do not claim that we have an inalienable "right to drive" - it is considered a driving "privilege", and one must pass certain tests to qualify. Likewise, the current "right to bear arms" is not generally extended to felons, nor to land mines and anti-aircraft missiles. Even so, there is an understood "right to travel" within the country, to access transportation services at a grass-roots level, to have privately controlled transport widely available, and to not have to file an itinerary with the government stating where you intend to go and whom you intend to see, nor even to know what you may be transporting (in the absence of independent evidence of crime). Thus, with some degree of interpretation, we arguably exercise a "right" to access private and personal transportation.
Together with the original Second Amendment, we thus have the acronym "FACET" to recall "Food, Arms, Communications, Energy, and Transportation". The reinterpreted Second Amendment, with respect to:
Food: "A well-stocked marketplace being necessary to secure health and well-being, the right of the people to local food production and trade shall not be infringed".
Arms: "A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed."
Communications: "Effective communications being critical to the defense of a free state, the right of the people to secure messaging and an open Internet shall not be infringed."