Off topic a little, just an observation.
WWI, WWII, Korea and Viet Nam all have something in common.
When each war began the military did not have enough trained men to fight the war. The draft swelled the ranks of young man who would all face combat for the first time with mostly others that have never fought before.
I don’t think since the American Civil War has there been so many combat veterans in civilian life.
I was first against the idea of trying to fight a war with National Guard units, I admit I had a bias against them and did not think they would perform well. I was wrong.
By using National Guard troops we have not need a draft (and all the problems associated with a draft) but an added yet unrealized bonus is we have a very large number of men and woman in civilian life who have been to war, know what it is, and are capable of quickly responding again if needed.
I have had an uneasy feeling for a long time that we will at some point in our future be in a “real” war. Real in the sense it will be more like WWII then what we are fighting now. When it begins we will not be at the disadvantage in trained manpower we were at the beginning of WWII which is good because things move a lot quicker now than it did then.
I question some of your conclusions.
In 1970 the active duty was 3.1 million, in 1965 it was 2.7 million, in 1960 it was 2.5 million. We weren’t all that short of men at the start of the Vietnam war.
The draft did increase, but during the Vietnam war (draft dates of ten years)(Aug 1964- Feb 1973) 1,857,304 men were drafted, which was only about 4 or 500,000 more than had been drafted (draft dates of 10 years) (1954-1963) since the end of the Korean war draft.
The Vietnam military was overwhelmingly a volunteer force, and the Guard and Reserves were about 10% of the war deaths.
I think that our current pool of combat vets is probably smaller than it has been in generations, the small number of GIs cycling through our current wars are not nearly enough to make up for the massive loss of our WWII, Korea, and Vietnam combat vet pool that has been dying off in the last 10 or 20 years.
I do agree with your point of feeling uneasy about what I call our “bench depth” if we get involved in a massive war, our shallow military strength will be revealed as our small but superb combat forces suffer decimation, with little relief and replacement showing up.