It would be one hell of a deterrent to a would-be foreign invader if they knew that the Pentagon could have 50-100 million trained men under combat arms within 24-48 hours max. The Border Patrol or locally-operating SF units (for example) would have a massive "weekend warrior" volunteer army. Free, military manpower, would be a major asset to commanders and law enforcement personnel operating in the border regions. The political climate would have to change in the US for Congress to mandate that every city and town set up a local, official militia by force of law.
I bet people would line up in DROVES. I am not sure if the command structure could handle the massive influx of volunteers at first. Special Forces ODA (6) and ODB (6) units (12 man teams) could effectively supervise a few hundred unpaid, all-volunteer weekend warriors. As more training was required, military "advisers" with different MOSes could be brought in for specific types of advanced training. For example, how to use NVG, FLIR or remote ground sensors to spot or detect targets along the border for air assault/interdiction units. The weekend warriors would cost the taxpayer far less than a 50 million man permanent standing garrisoned army.
The only up front costs would be regional arsenals and training centers with new M4s, M-60s, SAWs etc and some additional NVG/FLIR technology. Older military hardware like deuce and a halfs could be passed down and recycled, rather than sitting around rusting. The taxpayer would get the maximum use of the military dollar, stretching the years of useful life on every truck, every humvee out another 20 or 30 years. Even the Sheridan tank could be handed down when airborne loses this great asset.
Weekend volunteers could be reasonably expected to pay for their own uniforms and MREs if they wanted to play the game. As leadership was exhibited, the best trainees could get honorary rank and be candidates for OCS, an ROTC program or direct application for recruitment into one of the branches of the service. Recruiters would be encouraged to be present and in the field at all USA Militia meetings, rather than drive around cities or sit behind desks. Coordination with local FEMA branches could be organized. The possibilities are endless. We desperately need an Eagle Scout type of volunteer militia to encourage good citizenship; promote responsibility; provide firearms training and safety procedure; enhance national security, and; provide trained resources should local communities have the need in time of emergency (and budgetary constraints).
If you know any government officials, or if you know the right agency, I would pitch this idea . It sounds plausible, although numbers seem a bit high to me, but less would be a good back up for USA. It was how the US gained its independence from Britain. A militia worked then and it would be a great benefit for the borders. I realize a lot would be older, retired or not eligible for Reserves, but it makes sense.
I am not as knowledgable as you on weapons and type of military operable gear/machinery available. I am sure the military would gladly receive a little help on homefront.
It might show that the draft is not needed, enough patriots out there to protect us.
My only concern is there are a few 'over the edge' types in some of the militia around, who concern the government. How would you handle them?