U.S. Mobilization

This question kind of relates to a previous post about U.S. troop numbers. For the U.S. mobilizing some 16 million by 12/46, and roughly 13 million by the end of combat for all branches and services, why did it seem like they had such small actual combat numbers and combat troops fighting in Europe. Everything I've read states that high command was worried about fighting manpower in the ETO when the U.S. had already mobilized millions, and peak Army strength alone was almost 9 million, including 2.7 million for AGF. You would think they would have used massive advances like the Russians did, as their population and ours was not much different and we had a pool of 25 million men. I also know the logistical issues and the fact that we wanted manufacturing as our number one weapon, and that we didn't fully mobilize all African-Americans.

 

Well, if we compare our forces to the German's and USSR's they're quite different. The USA had a HUGE air force (then technically part of the army). We also had an even larger navy. Neither Germany or the Soviets had anything comparable. Both those services had a lot of advanced technology so they needed very large training and logistical organs to keep the ships and planes working which consumed a lot of manpower. The army itself had a huge logistical tail which used a lot of men. Also, initially our army put a lot more of out manpower into non-combat units, or units such as anti-aircraft and coastal defense that weren't needed all that much. Later, these units were combed out to provide replacements.

The other factor is our organizational philosophy. Our Army's doctrine was to figure how many divisions we would need and also how many we could keep at full strength once combat was initiated. Even then we somewhat underestimated our need for replacements. (How those replacements were filtered into the combat units is controversial, but that's another story.) Unlike us, the Germans and Soviets had more divisions but would fight those divisions until they were only a shell, then bring those units out of the line to be rebuilt. In a nutshell, the USSR and the Germans had a much leaner logistics system with a larger percentage of their men in combat units, with fewer men in their navies and air forces. And it should be added that while both Germany and the USSR had more divisions, often those divisions weren't nearly up to strength. Oh yes, while we only had just over 80 divisions in Europe, at most, we also had many independent artillery and armored battalions.

Had the war gone for any significantly longer time I'm sure we would have seen many more black units.

 

The other thing you have to consider is the tremendous amount of paperwork that it took to run the military in 1941-45. Somewhere I have quoted a statistic that is to the affect: "For every one front line soldier there are nine others who are supporting him". That support chain reached from the front line all the way back to the US. As the war progressed Germany's logistic chain got shorter while the US and Russian chain got longer. So, as Germany collapsed on it's self they were able to sacrifice more support personnel in combat.

As Harrolds said above: The Germans and the Russians had a much leaner logistics system.

 

That's a good point about the Navy and Air Force, and that alone our total Naval personnel to serve during the war, 4.4 million, would have made over 400 Russian divisions as they had a tiny navy. And also many of our combat units were non-divisional and independent battalions, as someone had mentioned. Also, about half of AGF were non-divisional combat forces. Our Air Force was also around 3 plus million if I recall, which is 300 Russian divisions, as they arranged them at 10k, running them understrength also. America relied more on air supremacy, a powerful fleet with the biggest Aircraft Carrier force the world had ever seen that could have wiped out any enemy.

 

If you are looking at divisions it's also worth noteing that US divisions once you add in the attachements usually operated at well over their nominal divisional personel strength. German and Soviet divisions on the other hand especially near the end of the war were often operating at under 70% and sometimes approaching 50% from what I've read.

 

from Rich Relations : on 31 may 1944,the US had 20 divisions in Britain = a field force of 640.635 men = a divisional slice of 32000 men .

 

The "divisional slice" typically refers to the porportion of higher level forces that would support a division as such it wouldn't include the actual troops in the division. So in the case of the above if a US division nominally had 10,000 men the divisional slice of the troops in Britain would be on the order of 22,000. I seem to recall reading that the combat strength of some/many US divisions exceeded 15,000 though and may have exceeded 20,000 but that was with attached units which may or may not have been considered part of the "division slice".

On the other hand there were parts of the support structure that stretched all the way back to the US so your numbers do make it clear that one simply can't divide the number of troops by some arbitrary figure to get the number of divisions. Note that USMC divisions drew a lot of their support from the USN and for that matter so did army troops in the Pacfic and for a while those that landed on D-day.

 

From a US stats site they listed the US strength in England by D-Day was 1.5 million men.

 

Yes,but I intentionally mentioned : field forces .

1.5 million was the total number :field forces :640.000,air forces : 426.000,,service troops:366.000,non operating :93000 (mainly sick)

 

The sudden drive across France and the logistical difficulties absolutely account for the slim number of US divisions in Europe.

Read this chapter:
http://www.ibiblio.org/hyperwar/USA/USA-E-Logistics2/USA-E-Logistics2-10.html

From the logistics point of view they advanced the flow of divisions but the situation demanded more.


I like Gen Marshall's initiative but I don't think Eisenhower and Bradley made it happen.

Hard to "not consider the experiment successful " when it was not even tried. The infantry regiments used by 6th Army Group were grouped three to a veteran division, not one to each veteran division as Marshall planned. Now, of course, the presence of those nine infantry regiments were absolutely critical for 6th AG to cover for the Third Army (12th AG) and defeat NORDWIND, all outside Bradley's view.

 

I clicked on that link.... The chart they list shows a steady flow of at least 1.5 million Americans in England and the ETO, and by the Spring of 1945 we had 3 million in the ETO, including over 1.5 million just in combat roles. If that number is steadily reinforced like it was to keep it at a stable number, along with the other allies, that's more than enough troops with the overwhelming materiel we had along with air power.