Some of us might be fimiliar with this book. Some of you might not.
Brief skim over on what it is
http://en.wikipedia.org/wiki/Watch_on_the_Rhine_(book)
So the debate. I doubt this go far

Is are you for it or are you against it (like this will ever happen) to reactivate those types of units.
I be for it due to they probaly would be the last to even be considered for the process. I would even go as far as getting a slice element and throwing bodies for them to train and assist the US (our soil not Germany) in defense and eventually repealing the invaders. An invasion of that scale will need every combat experience soldier we can get our hands on. I even take the insurgents in Gitmo and team them up with partisan units behind the lines (mountain defense so east and west coast plains action). I go pretty far to protect the human race. How far are you willing to go. Stick with the book but add more to what you would do to succed.
I empty out prison system and form construction Battalions. They stay in the battalions till their time is up and then will recieve promotions in just that Battalion. The more hardcore minded ones I put in the mines....along with looters, rapiest, black marketers, and murderers.
Fighting age will be dropped to 17 for all males and females. Anyone else not military fit will go into war production.. Just to start.