My sources aren't entirely consistent.
From here (a Congressional Research Service report).
From USAFacts.org.
Note that the total number of active duty personnel in the U.S. military has fallen from the peak of the Iraq War/Afghan War era, to close to the 1940 levels (not replicated in absolute levels since of a little under 600,000 active duty soldiers and sailors) on a personnel per capita basis when the U.S. had 40% of its current population.
Also, it is worth noting that the peak number of personnel deployed in these wars was facilitated with stop-loss orders for existing personnel (i.e. by prohibiting them from leaving the military at the end of the term that they signed up for), heavy deployment of reserve and national guard forces, and even limited reassignments from one service (e.g. the U.S. Navy) to work on missions primarily being handled by another service (e.g. the U.S. Army).
Thus, peak deployments in these conflicts is a good rough estimate of the maximum number of ground troops that can be deployed to a foreign war at any one time, without abandoning other foreign bases or wholesale transfers of personnel from one service to the other. Indeed, the peak deployment capacity of the U.S. military now is probably less than it was then, due to the reduced number of active duty personnel serving today.
Roughly speaking, the U.S. can deploy about 1/7th of its total number of active duty personnel on the ground in a foreign war while tapping reserve and national guard forces to the greatest extent possible in a time period after air superiority is achieved.
About half of that amount is due to U.S. Navy and U.S. Air Force troops not being available and/or useful in conflicts where air superiority is achieved and there are no naval battles to fight.
Some of the rest comes from ongoing commitments to man foreign bases in places like South Korea and Japan and Germany.
Some of the rest comes from having some personnel who aren't suitable for that particular conflict in a forward base due to the nature of their specialized training or the fact that they are still, for example, in basic training.
The balance of the limitation is due to the need to rotate troops periodically, rather than keeping them indefinitely in the field in war zones.
The bottom line is that while the U.S. military has by far the most expensive military in the world, with the most high end military systems, and is reasonably well trained, it does not have particular great numbers of deployable ground troops.
Hum... At the beginning of WW2 the Army staff projected that the US could create and deploy 300 divisions. Roughly comparable to what Germany and Russia could and would deploy. Then the detailed planning began, after looking at the resources need to build the primary factories to create the raw materials to feed the secondary factories to create the materials needed to equip and deploy the forces, (breath) they cut the numbers back to 150 divisions. Later replans looking at personnel resources and shipping limitations cut it down to 100 divisions with actual army division numbers topping out around 90. It takes a lot of infrastructure to put 100,000 boots on the ground 1/2 way around the world.
ReplyDeleteCheers,
Guy
(sources: the Green Book, esp The Army and Economic Mobilization and The Army and Industrial Manpower.)
I'm obviously only looking at the status quo, not the potential for ramp up. This is in part because any ramp up couldn't happen fast enough for a military incident to become a fait accompli.
ReplyDeleteAlso, the economics now v. WWII are quite different.
Also, 90 infantry divisions = 1,800,000 troops, more or less, which would more than double the current active duty strength of the U.S. military. And, 90 divisions in the force does not really mean 90 divisions deployable at any one time abroad.